infovis95--528697 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Case study: 3D displays of Internet traffic. The explosive growth in world-wide communications, especially the Internet, has highlighted the need for techniques to visualize network traffic. The traditional node and link network displays work well for small datasets but become visually cluttered and uninterpretable for large datasets. A natural 3D metaphor for displaying world-wide network data is to position the nodes on a globe and draw arcs between them coding the traffic. This technique has several advantages of over the traditional 2D displays, it naturally reduces line crossing clutter, provides an intuitive model for navigation and indication of time, and retains the geographic context. Coupling these strengths with some novel interaction techniques involving the globe surface translucency and arc heights illustrates the usefulness for this class of displays. interaction geographic network case study data visualisation Internet telecommunication computing navigation Eick, S.G. InfoVis computer animation navigation large data sets Cox, K.C. 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on stereo image processing telecommunication traffic 3D displays Internet traffic arc height geographic context globe surface translucency line crossing clutter reduction network traffic visualisation time indicator world-wide communications world-wide network data infovis95--528696 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Case study: visualizing Internet resources. The goal is to improve the ability of people from all walks of life and interests to access, search, and use the information distributed in Internet resources. The process of interacting with information resources starts with browsing, continues with digesting and assimilating pieces of information, terminates with generation of new information, and begins anew with analysis of pre-existing and new information. Our approach is user-centric-taking users needs into account by allowing them to interact with the information contained in large arrays of documents. The visualization process is an integral part of the overall process. We have covered three related categories in this methodology. The first one is browsing through the World-Wide Web (WWW) hyperspace without becoming lost, based on a visual representation of the hyperspace hierarchical structure (hyperspace view). The second category is overcoming the rigidity of the WWW by allowing the user to construct interactively and visually a personal hyperspace of information, linking the documents according to the application or problem domain, or to the user's own perception, experience, culture, or way of thinking. The third category includes discovery and analysis of new information and relationships in retrieved documents by aggregating relevant information and representing it visually. case study data visualisation Internet information analysis information retrieval visual representation perception InfoVis browsing 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Gershon, N. LeVasseur, J. Winstead, J. Croall, J. Pernicks, A. Ruh, W. Internet resource visualisation World-Wide Web hyperspace document linking documents hyperspace hierarchical structure information resource interaction new information analysis new information discovery personal information hyperspace retrieved documents user-centric approach infovis95--528695 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Case study: an empirical investigation of thumbnail imag recognition. The use of thumbnails (i.e., miniatures) in the user-interface of image databases allows searching and selection of images without the need for naming policies. Treating parent images prior to reduction with edge-detecting smoothing, lossy image compression, or static codebook compression resulted in thumbnails where the distortion caused by reduction was lessened. An experiment assessing these techniques found resulting thumbnails could be recognised more quickly and accurately than thumbnails of the same parent images that had been reduced without treatment. This pretreatment in thumbnail creation is offered as an improvement. case study data visualisation visual databases user interfaces user interface experiment distortion InfoVis data compression 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Burton, C.A. Johnston, L.J. Sonenberg, E.A. edge detection image coding edge-detecting smoothing image databases image reduction image selection lossy image compression parent image treatment searching static codebook compression thumbnail creation thumbnail image recognition infovis95--528694 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Case study. A WWW viewpoint on scientific visualization: an EPA case study for technology transfer. The paper examines how to provide scientific visualization capabilities to environmental scientists, policy analysts and decision makers with personal computers (PCs) on their desktops. An approach for using the World Wide Web (WWW) for disseminating knowledge on scientific visualization and for intelligent access to visualization capabilities on high performance (UNIX) workstations is outlined. case study data visualisation Internet information retrieval InfoVis world wide web World Wide Web 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on workstations Rhyne, T.M. Unix environmental science computing government data processing information dissemination microcomputer applications operating systems (computers) public administration technology transfer EPA case study decision makers environmental scientists high performance UNIX workstations intelligent visualization capability access knowledge dissemination personal computers policy analysts scientific visualization capabilities infovis95--528693 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Case study: fishing for information on the Internet. As the Internet continues to grow, the amount of accessible information becomes increasingly vast. Search tools exist that allow users to find relevant information. However, a search can often produce such a large amount of data that it becomes hard to ferret out the most appropriate and highest quality information. In addition, some search tools lose valuable information when displaying the results to the user. The paper describes a search visualization tool, called FISH, for viewing hierarchically structured information and managing information overload. FISH (Forager for the Information Super Highway) allows users to visualize the results of search requests across large document spaces in a way that preserves the structure of the information space. FISH displays the returned documents as rectangles, using a combination of order, indentation, size, and color to denote document hierarchy, the score of the documents with respect to the search, and other data attributes. In addition, the user can navigate through the document space for in-depth probing and refinement. document case study data visualisation Internet information retrieval hierarchy InfoVis color online front-ends 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Mitchell, R. Day, D. Hirschman, L. FISH search visualization tool color data attributes document hierarch hierarchically structured information viewing indentation information overload management large document spaces order returned documents search requests search tools size user navigation infovis95--528692 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Case study. Visualising cyberspace: information visualisation in the Harmony Internet browser. The explosive growth of information systems on the Internet has clearly demonstrated the need to organise, filter, and present information in ways which allow users to cope with the sheer quantities of information available. The scope for visualisation of Gopher and WWW spaces is restricted by the limitations of their respective data models. The far richer data model supported by the Hyper-G Internet information system is exploited by its Harmony client to provide a number of tightly-coupled, two- and three-dimensional visualisation and navigational facilities, which help provide location feedback and alleviate user disorientation. case study data visualisation Internet filter information retrieval InfoVis data structures Andrews, K. information systems hypermedia navigational facilities 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on information visualisation information systemsGopher spaces Harmony Internet browser Harmony client Hyper-G Internet information system WWW spaces cyberspace visualisation data models location feedback infovis95--528691 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Case study. Narcissus: visualising information. It is becoming increasingly important that support is provided for users who are dealing with complex information spaces. The need is driven by the growing number of domains where there is a requirement for users to understand, navigate and manipulate large sets of computer based data; by the increasing size and complexity of this information and by the pressures to use this information efficiently. The paradigmatic example is the World Wide Web, but other domains include software systems, information systems and concurrent engineering. One approach to providing this support is to provide sophisticated visualisation tools which lead the users to form an intuitive understanding of the structure and behaviour of their domain and which provide mechanisms which allow them to manipulate objects within their system. The paper describes such a tool and a number of visualisation techniques that it implements. case study data visualisation information retrieval InfoVis world wide web navigation information systems concurrent engineering virtual reality World Wide Web data manipulation 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on visualisation tools information networks information visualisation Hendley, R.J. Drew, N.S. Wood, A.M. Beale, R. adaptive systems programming environments self-adjusting systems visual programmingNarcissus complex information spaces intuitive understanding large computer based data sets object manipulation software systems user support infovis95--528690 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Research report. DataSpace: 3-D visualizations of large databases. DataSpace is a system for interactive 3-D visualization and analysis of large databases. DataSpace utilizes the display space by placing panels of information, possibly generated by different visualization applications, in a 3-D graph layout, and providing continuous navigation facilities. Selective rearrangements and transparency can be used to reduce occlusion or to compare or merge a set of images (e.g. line graphs or scatter plots) that are aligned and stacked in depth. A prototype system supporting the basic 3-D graphic operations (layout, zoom, rotation, translation, transparency) has been implemented. We provide several illustrative examples of DataSpace displays taken from the current system. We present the 3-D display paradigm, describe the query, layout and rendering steps required to create a display, and discuss some performance issues. graph graph layout data visualisation data analysis navigation zoom InfoVis query processing occlusion computer displays transparency interactive 3D visualization very large databases large databases 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Anupam, V. Dar, S. Leibfried, T. Petajan, E. 3D graph layout 3D graphic operations DataSpace continuous navigation facilities display space image comparison image merging information panels large database analysis layout step performance issues query step rendering step selective rearrangements infovis95--528689 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Research report. Interacting with huge hierarchies: beyond cone trees. The paper describes an implementation of a tool for visualizing and interacting with huge information hierarchies, and some preliminary empirical evaluation of the tool's efficacy. Existing systems for visualizing huge hierarchies using cone trees "break down" once the hierarchy to be displayed exceeds roughly 1000 nodes, due to increasing visual clutter. The paper describes a system called fsviz which visualizes arbitrarily large hierarchies while retaining user control. This is accomplished by augmenting cone trees with several graphical and interaction techniques: usage-based filtering, animated zooming, hand-coupled rotation, fish-eye zooming, coalescing of distant nodes, texturing, effective use of colour for depth cueing, and the applications of dynamic queries. The fsviz system also improves upon earlier cone tree visualization systems through a more elaborate node layout algorithm. This algorithm enhances the usefulness of cone tree visualization for large hierarchies by all but eliminating clutter. interaction zooming evaluation data visualisation hierarchy hierarchies InfoVis interaction techniques computer animation dynamic queries tree data structures cone trees visual clutter Kazman, R. Carriere, J. 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on animated zooming colour cone tree visualization systems depth cueing distant node coalescence empirical evaluation fish-eye zooming fsviz graphical techniques hand-coupled rotation huge hierarchies huge information hierarchy interaction huge information hierarchy visualisation node layout algorithm texturing tool efficacy usage-based filtering user control infovis95--528688 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on IVEE: an Information Visualization and Exploration Environment. The Information Visualization and Exploration Environment (NEE) is a system for automatic creation of dynamic queries applications. IVEE imports database relations and automatically creates environments holding visualizations and query devices. IVEE offers multiple visualizations such as maps and starfields, and multiple query devices, such as sliders, alphasliders, and toggles. Arbitrary graphical objects can be attached to database objects in visualizations. Multiple visualizations may be active simultaneously. Users can interactively lay out and change between types of query devices. Users may retrieve details-on-demand by clicking on visualization objects. An HTML file may be provided along with the database, specifying how details-on-demand information should be presented, allowing for presentation of multimedia information in database objects. Finally, multiple IVEE clients running on separate workstations on a network can communicate by letting one user's actions affect the visualization in an another IVEE client. network data visualisation database InfoVis query processing computer animation query formulation multimedia computing 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on workstations Ahlberg, C. Wistrand, E. HTML file IVEE Information Visualization and Exploration Environment alphasliders arbitrary graphical objects automatic dynamic query creation database objects database relations details-on-demand retrieval maps multimedia information multiple IVEE clients multiple query devices multiple visualizations network query devices sliders starfields toggles user actions infovis95--528687 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on VRMosaic: WEB access from within a virtual environment. Virtual reality can aid in designing large and complex structures such as ships, skyscrapers, factories, and aircraft. But before VR can realize this potential, we need to solve a number of problems. One of these problems: the user's need to see and interact with non-geometric information is examined. Our VR environment, RealEyes, can display large-scale and detailed geometry at reasonable frame rates (>20 Hz) allowing a user to see and navigate within a design from a first person perspective. However, much (if not most) of the information associated with a particular design has no geometric representation. This includes information such as schematics of electrical, hydraulic, and plumbing systems; information describing materials or processes; and descriptive (textual) information of other types. Many researchers have developed a wealth of techniques for presenting such data on flat-screen displays, but until recently, we have not had a means for naturally displaying such information within a VR environment. To make non-geometric data more available, we have implemented a version of Mosaic that functions within a fully immersive VR system. Our system, VRMosaic, allows a user of VR to access and display most of the data available using flat screen Mosaic. Moreover, we have made it extensible to allow for the seamless integration of specialized forms of data and interaction. This paper describes how we implemented VRMosaic using a VR-capable version of Interviews, It also describes some Mosaic-like uses of that system and some "non-Mosaic-like" extensions. interaction data visualisation InfoVis computer displays virtual reality 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on information networks Angus, I.G. Sowizral, H.A. RealEyes VR-capable Interviews VRMosaic Web access detailed geometry display first person perspective flat screen Mosaic frame rates fully immersive VR system large-scale geometry display nongeometric data nongeometric information virtual environment infovis95--528686 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Visualizing the non-visual: spatial analysis and interaction with information from text documents. The paper describes an approach to IV that involves spatializing text content for enhanced visual browsing and analysis. The application arena is large text document corpora such as digital libraries, regulations and procedures, archived reports, etc. The basic idea is that text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The spatial representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts mental workload. The result is an interaction with text that more nearly resembles perception and action with the natural world than with the abstractions of written language. interaction document text data visualisation visual databases Thomas, J. information retrieval visual analysis perception InfoVis digital libraries Crow, V. 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Wise, J.A. Pennock, K. Lantrip, D. Pottier, M. Schur, A. libraries library automation word processingaction archived reports information interaction informational characteristics large text document corpora natural world nonvisual visualization perception procedures regulations spatial analysis spatial representation text content text content spatialization text documents visual browsing infovis95--528685 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on The information mural: a technique for displaying and navigating large information spaces. Visualizations which depict entire information spaces provide context for navigation and browsing tasks; however, the limited size of the display screen makes creating effective global views difficult. We have developed a technique for displaying and navigating large information spaces. The key concept is the use of an information mural, a two-dimensional reduced representation of an entire information space that fits completely within a display window or screen. Information murals use grayscale shading and color along with anti-aliasing techniques to create a miniature version of the entire data set. By incorporating navigational capabilities, information murals become a tool that can be used as a global view along with more detailed informational displays. Information murals are utilized in our software visualization research to help depict the execution of object-oriented programs, and can also be used in more general information visualization applications. data visualisation Stasko, J. user interfaces navigation InfoVis color data visualization colour graphics software visualization visual programming software visualization object-oriented programming browsing information navigation 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Jerding, D.F. antialiasing antialiasing techniques color graphics display screen global views grayscale shading information display information mural large information spaces object-oriented programs infovis95--528684 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on SDM: malleable information graphics. Selective dynamic manipulation (SDM) is a paradigm for interacting with objects in visualizations. Its methods offer a high degree of selectivity, in choosing object sets, in the selection of interactive techniques and the properties they affect, and in the degree to which a user action affects the visualization. Our goal is to provide a flexible set of techniques and feedback mechanisms that enable users to move objects and transform their appearance to perform a variety of information analysis tasks. visualization data visualisation interactive systems graphical user interfaces InfoVis direct manipulation Chuah, M.C. Roth, S.F. interactive techniques visualizations Kolojejchick, J. direct manipulation interactive techniques 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Mattis, J. SDM information analysis tasks malleable information graphics object set selection selective dynamic manipulation user action infovis95--528683 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Research report: improving browsing in information by the automatic display layout. It is well known that graphical representations could be very helpful to browse in graph structured information. But this promising approach requires the capability of an automatic layout system because the tedious and time consuming task of a manual layout leads to a rejection of this approach by the user. In our approach, we split the task of retrieving information into two phases that are getting the orientation within the network and reading currently visited information. We present layout algorithms for both phases which have the benefit of being flexible and adaptable to individual user requests and ensure the topological consistency, i.e. the stability of the topology of the information layout during a sequence of display layouts. The results show that especially the possibility of an animation of the layout process can assist the user essentially in maintaining the orientation in the information network. network graph graphical user interfaces information retrieval animation InfoVis computer animation human factors graphical representations 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Luders, P. Ernst, R. user modelling automatic display layout automatic layout system display layouts graph structured information information browsing information network layout algorithms manual layout time consuming user model user requests infovis95--528682 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Research report: information animation applications in the capital markets. 3D computer graphics can be extremely expressive. It is possible to display an entire securities market, like the S&P 500, on a single screen. With the correct approach to the visual design of the layout, these massive amounts of information can be quickly and easily comprehended by a human observer. By using motion and animated interaction, it is possible to use 3D as a reliable, accurate and precise decision-support tool. Information animation applications are particularly suited to the securities industry because that is where we find huge amounts of data, the value of which declines rapidly with time, and where critical decisions are being made on this data in very short periods of time. Information animation technology is an important new tool for the securities industry, where people need to be in the decision-making loop without suffering from information overload. Several examples are discussed including equity trading analytics, fixed income trading analytics and fixed-income risk viewing. interaction data visualisation Wright, W. animation InfoVis computer animation financial data processing risk management 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on decision support systems securities trading 3D computer graphics capital markets decision-support tool equity trading analytics fixed income trading analytics fixed-income risk viewing information animation applications securities industry securities market three dimensional computer graphics visual design infovis95--528681 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Towards a generative theory of diagram design. We describe the theoretical background for AVE, an automatic visualization engine for semantic networks. We have a functional notion of aesthetics and therefore understand meaningfulness as a central issue for information visualization. This implies that the diagrams should communicate the characteristics of the data as effectively as possible. In this generative theory of diagram design, we include data characterization, systematic use of graphical means of expression and the combination of graphical means of expression. After giving a brief introduction and an application scenario we discuss these aspects in detail. Finally, a process model of an automatic visualization process is sketched and directions for further research are outlined. data visualisation theory information visualization InfoVis aesthetics aesthetics diagrams data characterization 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on CAD Reichenberger, K. Kamps, T. Golovchinsky, G. semantic networksAVE automatic visualization engine automatic visualization process diagram design process model semantic networks infovis95--528680 10/30/1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on Visualisation for functional design. We present two novel visualisation tools: the Influence Explorer and the Prosection Matrix. These were specifically created to support engineering artifact design and similar tasks in which a set of parameter values must be chosen to lead to acceptable artifact performance. These tools combine two concepts. One is the interactive and virtually immediate responsive display of data in a manner conducive to the acquisition of insight. The other, involving the precalculation of samples of artifact performance, facilitates smooth exploration and optimisation leading to a design decision. The anticipated benefits of these visualisation tools are illustrated by an example taken from electronic circuit design, in which full account must be taken of the uncertainties in parameter values arising from inevitable variations in the manufacturing process. insight data visualisation interactive systems matrix user interfaces InfoVis optimisation 1995 Information Visualization, 1995. (InfoVis '95) Proceedings. 1995 IEEE Symposium on visualisation tools CAD Spence, B. Tweedie, L. Dawkes, H. Su, H. circuit CAD engineering graphics Influence Explorer Prosection Matrix electronic circuit design engineering artifact design functional design interactive display manufacturing process infovis96--559229 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Visualizing a tennis match. This paper describes our work on visualizing the information of a tennis match. We use competition trees to organize the information of a tennis match and visualize the competition trees by the top-nesting layered maps with translucent colored layers. We create iconic representations to describe the detailed information of athletic events in an intuitive manner. Specialized views of the information are displayed by applying multiple Magic Lens filters on the top-nesting layered maps. The dynamic nature of the tennis match is depicted by the time-varying display. The approach we present in this paper can be used to visualize other sports information, information with competition property, or information with hierarchical structure data visualisation InfoVis tree data structures 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Jin, L. Banks, D.C. sport athletic events competition property iconic representations tennis match top-nesting layered maps visualizing infovis96--559228 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on DEPICT: Documents Evaluated as Pictures. Visualizing information using context vectors and self-organizing maps. HNC Software, Inc. has developed a system called DEPICT for visualizing the information content of large textual corpora. The system is built around two separate neural network methodologies: context vectors and self-organizing maps. Context vectors (CVs) are high dimensional information representations that encode the semantic content of the textual entities they represent. Self-organizing maps (SOMs) are capable of transforming an input, high dimensional signal space into a much lower (usually two or three) dimensional output space useful for visualization. Neither process requires human intervention, nor an external knowledge base. Together, these neural network techniques can be utilized to automatically identify the relevant information themes present in a corpus, and present those themes to the user in a intuitive visual form network data visualisation self-organising feature maps visualization InfoVis document handling neural nets 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Rushall, D.A. Ilgen, M.R. DEPICT context vectors documents evaluated as pictures information representations self organizing maps textual corpora textual entities visualizing information infovis96--559227 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Visualizing usability log data. Our approach to testing graphical user interfaces involves logging large amounts of data. These logs capture information at the key press and mouse click level about how an application is used. Since the raw data is voluminous and not at a useful level of detail, we use analysis and visualization to find information that is interesting and useful to a usability analyst but was previously buried in the data. We call some of our custom visualizations ?contextual? meaning they use key elements of the context the data was collected in as an organizing structure. We expect this type of visualization to be easier and faster to understand and more helpful than traditional charts. We hope that our finding a natural geometry for these visualizations will inspire others whose data apparently has no inherent geometry to find natural ways to visualize their data usability data visualisation data analysis graphical user interfaces InfoVis human factors 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Gray, M. Badre, A. Guzdial, M. program testingcharts custom visualizations data logging geometry graphical user interface testing key press mouse click organizing structure usability analysis usability log data visualisation infovis96--559226 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Visualizing the global topology of the MBone. We present a case study of visualizing the global topology of the Internet MBone. The MBone is the Internet's multicast backbone. Multicast is the most efficient way of distributing data from one sender to multiple receivers with minimal packet duplication. Developed and initially deployed by researchers within the Internet community, the MBone has been extremely popular for efficient transmission across the Internet of real-time video and audio streams such as conferences, meetings, congressional sessions, and NASA shuttle launches. The MBone, like the Internet itself grew exponentially with no central authority. The resulting suboptimal topology is of growing concern to network providers and the multicast research community. We create a geographic representation of the tunnel structure as arcs on a globe by resolving the latitude and longitude of MBone routers. The interactive 3D maps permit an immediate understanding of the global structure unavailable from the data in its original form as lines of text with only hostnames and IP addresses. Data visualization techniques such as grouping and thresholding allow further analysis of specific aspects of the MBone topology. We distribute the interactive 3D maps through the World-Wide Web using the VRML file format thus allowing network maintainers throughout the world to analyze the structure move effectively than would be possible with still pictures or pre-made videos geographic network text case study Munzner, T. data visualisation interactive systems Internet user interfaces InfoVis data visualization Hoffman, E. virtual reality real-time systems 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Claffy, K. Fenner, B. multimedia communication IP addresses Internet MBone MBone routers MBone topology visualisation NASA shuttle launches VRML World-Wide Web case study conferences congressional sessions geographic representation hostnames interactive 3D maps meetings minimal packet duplication multicast backbone multiple receivers real-time audio real-time video suboptimal topology tunnel structure infovis96--559225 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Geospatial metadata querying and visualization on the WWW using Java^TM applets. This paper presents the query and visualization interfaces of the Master Environmental Library (MEL) system. MEL uses the World Wide Web (WWW) to make accessible distributed data whose metadata conform to the Federal Geographic Data Committee's (FGDC) content standards for digital geospatial metadata. The interfaces are implemented as Java^TM applets and are more intuitive, interactive and possess greater functionality than their Hypertext Markup Language (HTML) counterparts. As well as querying, the interface allows users to visualize and manage the list of query results so that users can more quickly discover the datasets of real interest. Several new tools used to visualize attributes of the metadata are presented geographic data visualisation visual databases Internet geospatial user interfaces InfoVis query processing world wide web geographic information systems object-oriented languages World Wide Web hypermedia 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Alper, N. Stein, C. distributed databases page description languages Federal Geographic Data Committee HTML Hypertext Markup Language Java applets Master Environmental Library system WWW content standards datasets distributed data access geospatial metadata querying geospatial metadata visualization interactive system infovis96--559224 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Dual multiresolution HyperSlice for multivariate data visualization . We present a new multiresolution visualization design which allows a user to control the physical data resolution as well as the logical display resolution of multivariate data. A system prototype is described which uses the HyperSlice representation. The notion of space projection in multivariate data is introduced. This process is coupled with wavelets to form a powerful tool for very large data visualization data visualisation user interfaces Wong, P.C. InfoVis Bergeron, R.D. very large databases 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Crabb, A.H. systems analysis wavelet transforms HyperSlice representation data resolution logical display resolution multiresolution visualization design multivariate data visualization space projection system prototype very large data visualization wavelets infovis96--559223 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Animating multidimensional scaling to visualize N-dimensional data sets. Many techniques have been developed for visualizing multivariate (multidimensional) data. Most, if not all, are limited by the number of dimensions which can be effectively displayed. Multidimensional scaling (MDS) is an iterative non-linear technique for projecting n-D data down to a lower number of dimensions. This work presents extensions to MDS that enhance visualization of high-dimensional data sets. These extensions include animation, stochastic perturbation, and flow visualization techniques high-dimensional data data visualisation user interfaces animation animation InfoVis multidimensional scaling multidimensional data computer animation multivariate data 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Bentley, C.L. data handling N-dimensional data set visualization flow visualization high-dimensional data sets iterative nonlinear technique multidimensional scaling animation stochastic perturbation multivariate data visualization infovis96--559222 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on FINESSE: a financial information spreadsheet. We outline a spreadsheet-based system for visualization of real-time financial information. Our system permits the user to define arithmetic and presentation relationships amongst the various cells of the spreadsheet. The cells contain primitives that can be numbers, text, images, functions and graphics. Presenting financial information in this format allows its intended clients, the financial analysts, to work in the familiar environment of a spreadsheet and allows them the flexibility afforded by the powerful interface of the spreadsheet paradigm. In addition, our system permits real-time visualization of the financial data stream allowing its user to visually trade the changing market trends in two and three dimensions text financial data visualisation user interfaces user interface Kaufman, A. InfoVis data visualization financial data processing real-time systems spreadsheet programs graphics 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Varshney, A. FINESSE arithmetic financial information spreadsheet functions images information presentation market trends numbers presentation real-time financial information spreadsheet cells text three dimensions two dimensions infovis96--559221 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Interactive visualization of multiway tables. Many business data visualization applications involve large databases with dozens of fields and millions of rows. Interactive visualization of these databases is difficult because of the large amount of data involved. We present a method of summarizing large databases which is well suited to interactive visualization. We illustrate this with a visualization tool for the domain of call billing data business data visualisation interactive systems user interfaces interactive visualization InfoVis financial data processing very large databases large databases 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Cox, K.C. Hackborn, D. business data processing invoicing public utilities business data visualization applications database summarizing multiway tables telephone call billing data visualization tool infovis96--559220 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Minimally-immersive interactive volumetric information visualization. This paper describes a minimally immersive volumetric interactive system for information visualization. The system, SFA, uses glyph-based volume rendering, enabling more information attributes to be visualized than traditional 2D and surface-based information visualization systems. Two-handed interaction and stereoscopic viewing combine to produce a minimally immersive interactive system that enhances the user's three-dimensional perception of the information space, capitalizing on the human visual system's pre-attentive learning capabilities to quickly analyze the displayed information. The paper describes the usefulness of this system for the visualization of document similarity within a corpus of textual documents. SFA allows the three-dimensional volumetric visualization, manipulation, navigation, and analysis of multivariate, time-varying information spaces, increasing the quantity and clarity of information conveyed from the visualization as compared to traditional 2D information systems interaction document data visualisation interactive systems user interfaces navigation Shaw, C. information visualization Ebert, D.S. perception InfoVis document handling rendering (computer graphics) glyph navigation human factors hypermedia 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Zwa, A. Miller, E.L. Roberts, D.A. 2D information visualization SFA document similarity glyph-based volume rendering human visual system hypertext information attributes minimally immersive volumetric interactive system multivariate time-varying information stereoscopic viewing surface-based information visualization textual documents three-dimensional perception three-dimensional volumetric visualization two-handed interaction user learning infovis96--559219 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Visualizing the results of multimedia Web search engines. Search engines are very useful because they allow the user to retrieve documents of interest from the World-Wide Web. However, if the user's query results in lots of records to be retrieved, just listing the results is not very user-friendly. We are developing a system that allows the visualization of the results. Visualizations of both text and image search are generated on the fly based on the search results text data visualisation Internet InfoVis data visualization query processing online front-ends multimedia computing World Wide Web 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Mukherjea, S. Hirata, K. Hara, Y. information retrieval systems document retrieval image search multimedia Web search engines text search user friendly infovis96--559218 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Towards rich information landscapes for visualising structured Web spaces. The Harmony browser for the Hyper-G Web server utilises Hyper-G's rich data model to provide a number of tightly-coupled, two- and three-dimensional visualisation and navigational facilities. In particular the Harmony Information Landscape visualises the hierarchical structure of Hyper-G spaces upon a plane in three-dimensional space. The Harmony Information Landscape has now been extended to display a combined structure and link map by selectively superimposing hyperlink relationships in the vertical dimension above and below the hierarchy map. In addition, documents returned by search queries may be selectively ?plotted? in the landscape, indicating their whereabouts in a broader context, and several sets of 3D icons are available for representing the various document types document data visualisation graphical user interfaces Internet hierarchy InfoVis data structures query processing Andrews, K. online front-ends hypermedia data model 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on navigational facilities Pichler, M. Wolf, P. 3D icons Harmony Information Landscape Harmony browser Hyper-G Web server document representation hierarchical structure hierarchy map hyperlink link map search queries three dimensional icons three-dimensional visualisation infovis96--559216 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Selection: 524,288 ways to say "this is interesting" . Visualization is a critical technology for understanding complex, data-rich systems. Effective visualizations make important features of the data immediately recognizable and enable the user to discover interesting and useful results by highlighting patterns. A key element of such systems is the ability to interact with displays of data by selecting a subset for further investigation. This operation is needed for use in linked-views systems and in drill-down analysis. It is a common manipulation in many other systems. It is as ubiquitous as selecting icons in a desktop GUI. It is therefore surprising to note that little research has been done on how selection can be implemented. This paper addresses this omission, presenting a taxonomy for selection mechanisms and discussing the interactions between branches of the taxonomy. Our suggestion of 524,288 possible systems [2^16 operation systems×2 (memory/memoryless)×2 (data-dependent/independent)×2 (brush/lasso)] is more in fun than serious, as within the taxonomy there are many different choices that can be made. This framework is the result of considering both the current state of the art and historical antecedents data visualisation graphical user interfaces taxonomy InfoVis data visualization Wills, G.J. 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on data manipulation complex data-rich systems data displays data subset selection desktop GUI drill-down analysis icon selection interesting results linked-views systems operation systems pattern highlighting recognizable data features selection mechanism taxonomy infovis96--559215 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Distortion viewing techniques for 3-dimensional data. As the use of 3D information presentation becomes more prevalent, the need for effective viewing tools grows accordingly. Much work has been done in developing tools for 2D spaces which allow for detail in context views. We examine the extension of such 2D methods to 3D and explore the limitations encountered in accessing internal regions of the data with these methods. We then describe a novel solution to this problem of internal access with the introduction of a distortion function which creates a clear line of sight to the focus revealing sections previously obscured. The distortion is symmetric about the line of sight and is smoothly integrated back into the original 3D layout data visualisation graphical user interfaces information visualization information visualization distortion InfoVis Carpendale, S. computer displays Fracchia, F.D. 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on technical presentation user interface design Cowperthwaite, D.J. three-dimensional displays 3D information presentation 3D interaction context views detail distortion viewing techniques focus internal access internal data regions line of sight screen layout smooth integration symmetric distortion function user interface metaphors distortion viewing screen layout 3D interaction interface metaphors interface design issues infovis96--559214 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Techniques for non-linear magnification transformations. This paper presents efficient methods for implementing general non-linear magnification transformations. Techniques are provided for: combining linear and non-linear magnifications, constraining the domain of magnifications, combining multiple transformations, and smoothly interpolating between magnified and normal views. In addition, piecewise linear methods are introduced which allow greater efficiency and expressiveness than their continuous counterparts data visualisation InfoVis computer displays Keahey, T.A. Robertson, E.L. 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on interpolation piecewise-linear techniques domain constraint efficiency expressiveness magnifications combination multiple transformations combination nonlinear magnification transformations normal views piecewise linear methods smooth interpolation infovis96--559213 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on On the semantics of interactive visualizations. Interactive techniques are powerful tools for manipulating visualizations to analyze, communicate and acquire information. This is especially true for large data sets or complex 3D visualizations. Although many new types of interaction have been introduced recently, very little work has been done on understanding what their components are, how they are related and how they can be combined. This paper begins to address these issues with a framework for classifying interactive visualizations. Our goal is a framework that will enable us to develop toolkits for assembling visualization interfaces both interactively and automatically interaction data visualisation interactive systems information analysis interactive visualization user interface InfoVis information visualization Chuah, M.C. Roth, S.F. graphics large data sets 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on user interface management systems interactive techniques automatic presentation systems complex 3D visualizations information acquisition information communication semantics visualization interface construction toolkits automatic presentation systems graphic infovis96--559212 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Rapid prototyping of information visualizations using VANISH. Discusses a software tool called VANISH (Visualizing And Navigating Information Structured Hierarchically), which supports the rapid prototyping of interactive 2D and 3D information visualizations. VANISH supports rapid prototyping through a special-purpose visual language called VaPL (VANISH Programming Language) tailored for visualizations, through a software architecture that insulates visualization-specific code from changes in both the domain being visualized and the presentation toolkit used, and through the reuse of visualization techniques between application domains. The generality of VANISH is established by showing how it is able to re-create a wide variety of ?standard? visualization techniques. VANISH's support for prototyping is shown through an extended example, where we build a C++ class browser, exploring many visualization alternatives in the process data visualisation interactive systems information visualization toolkit InfoVis visual programming software architecture software tools software tool visual languages 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on application domains Kazman, R. Carriere, J. information navigation software prototyping C++ class browser VANISH VaPL hierarchically structured information interactive information visualization presentation toolkit rapid prototyping visual language visualization techniques reuse visualization-specific code software tools visual programming languages infovis96--559211 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Data characterization for automatically visualizing heterogeneous information. Automated graphical generation systems should be able to design effective presentations for heterogeneous (quantitative and qualitative) information in static or interactive environments. When building such a system, it is important to thoroughly understand the presentation-related characteristics of domain-specific information. We define a data-analysis taxonomy that can be used to characterize heterogeneous information. In addition to capturing the presentation-related properties of data, our characterization takes into account the user's information-seeking goals and visual-interpretation preferences. We use automatically-generated examples from two different application domains to demonstrate the coverage of the proposed taxonomy and its utility for selecting effective graphical techniques Zhou, M.X. data visualisation data analysis taxonomy InfoVis human factors 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on technical presentation data characterization application domains Feiner, S.K. automated graphical generation systems automatic visualization automatically-generated examples data analysis taxonomy domain-specific information graphical technique selection heterogeneous information interactive environments presentation-related characteristics presentations design qualitative information quantitative information static environments user information-seeking goals visual interpretation preferences infovis96--559210 10/28/1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on Visage: a user interface environment for exploring information. Visage is a prototype user interface environment for exploring and analyzing information. It represents an approach to coordinating multiple visualizations, analysis and presentation tools in data-intensive domains. Visage is based on an information-centric approach to user interface design which strives to eliminate impediments to direct user access to information objects across applications and visualizations. Visage consists of a set of data manipulation operations, an intelligent system for generating a wide variety of data visualizations (SAGE) and a briefing tool that supports the conversion of visual displays used during exploration into interactive presentation slides. This paper presents the user interface components and styles of interaction that are central to Visage's information-centric approach interaction data visualisation interactive systems data analysis information analysis visualization InfoVis human-computer interaction exploratory data analysis information exploration Lucas, P. Roth, S.F. graphics Kolojejchick, J. Visage 1996 Information Visualization, 1996. (InfoVis '96) Proceedings. 1996 IEEE Symposium on technical presentation user interface design user interface management systems Senn, J.A. Gomberg, C.C. Burks, M.B. Stroffolino, P.J. Dunmire, C. data conversion SAGE briefing tool data manipulation operations data-intensive domains direct user access information-centric approach intelligent system interaction styles interactive presentation slides multiple data visualizations presentation tools user interface environment visual display conversion user interface environment infovis97--636794 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on Metrics for effective information visualization. Metrics for information visualization will help designers create and evaluate 3D information visualizations. Based on experience from 60+ 3D information visualizations, the metrics we propose are: number of data points and data density; number of dimensions and cognitive overhead; occlusion percentage; and reference context and percentage of identifiable points. data visualisation metrics InfoVis occlusion data density data points identifiable points 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on Brath, R. software metrics 3D information visualization cognitive overhead design dimensions information visualization metrics occlusion reference context infovis97--636793 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on Multidimensional detective. The display of multivariate datasets in parallel coordinates, transforms the search for relations among the variables into a 2-D pattern recognition problem. This is the basis for the application to visual data mining. The knowledge discovery process together with some general guidelines are illustrated on a dataset from the production of a VLSI chip. The special strength of parallel coordinates is in modeling relations. As an example, a simplified economic model is constructed with data from various economic sectors of a real country. The visual model shows the interelationship and dependencies between the sectors, circumstances where there is competition for the same resource, and feasible economic policies. Interactively, the model can be used to do trade-off analyses, discover sensitivities, do approximate optimization, monitor (as in a process) and provide decision support. parallel coordinates data visualisation parallel coordinates data mining InfoVis data structures pattern recognition Inselberg, A. 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on very large databases economics knowledge acquisition 2D pattern recognition problem VLSI chip approximate optimization competition decision support economic model economic policies economic sectors knowledge discovery modeling relations monitoring multidimensional detective multivariate dataset display trade-off analyses visual data mining infovis97--636792 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on The structure of the information visualization design space. Research on information visualization has reached the point where a number of successful point designs have been proposed and a variety of techniques have been discovered. It is now appropriate to describe and analyze portions of the design space so as to understand the differences among designs and to suggest new possibilities. This paper proposes an organization of the information visualization literature and illustrates it with a series of examples. The result is a framework for designing new visualizations and augmenting existing designs. data visualisation user interface Card, S.K. InfoVis information visualization Mackinlay, J.D. taxonomy 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on information visualization design space information visualization literature morphological analysis point designs research taxonomy design space morphological analysis infovis97--636791 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on Volume rendering for relational data. A method for efficiently volume rendering dense scatterplots of relational data is described. Plotting difficulties that arise from large numbers of data points, categorical variables, interaction with non-axis dimensions, and unknown values, are addressed by this method. The domain of the plot is voxelized using binning and then volume rendering. Since a table is used as the underlying data structure, no storage is wasted on regions with no data. The opacity of each voxel is a function of the number of data points in a corresponding bin. A voxel's color is derived by averaging the value of one of the variables for all the data points that fall in a bin. Other variables in the data may be mapped to external query sliders. A dragger object permits a user to select regions inside the volume. interaction data visualisation multivariate data categorical user interface information visualization information visualization InfoVis color data structures query processing rendering (computer graphics) scatterplot multivariate data data points Becker, B.G. relational data 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on relational databases categorical variables data structure dense scatterplots external query sliders nonaxis dimensions plotting relational data table unknown values volume rendering voxel volume rendering infovis97--636790 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on Design and evaluation of incremental data structures and algorithms for dynamic query interfaces. A dynamic query interface (DQI) is a database access mechanism that provides continuous real-time feedback to the user during query formulation. Previous work shows that DQIs are elegant and powerful interfaces to small databases. Unfortunately, when applied to large databases, previous DQI algorithms slow to a crawl. We present a new incremental approach to DQI algorithms and display updates that work well with large databases, both in theory and in practice. information visualization evaluation data visualisation Shneiderman, B. graphical user interfaces user interfaces theory information visualization database dynamic query InfoVis data structures query processing query formulation user interface real-time systems 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on very large databases query languages large databases visual languages Tanin, E. Beigel, R. DQI algorithms continuous real-time feedback database access mechanism dynamic query interfaces incremental data structures small databases data structure algorithm database direct manipulation and dynamic query infovis97--636789 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on Domesticating Bead: adapting an information visualization system to a financial institution. The Bead visualization system employs a fast algorithm for laying out high-dimensional data in a low-dimensional space, and a number of features added to 3D visualizations to improve imageability. We describe recent work on both aspects of the system, in particular a generalization of the data types laid out and the implementation of imageability features in a 2D visualization tool. The variety of data analyzed in a financial institution such as UBS, and the ubiquity of spreadsheets as a medium for analysis, led us to extend our layout tools to handle data in a generic spreadsheet format. We describe the metrics of similarity used for this data type, and give examples of layouts of sets of records of financial trades. Conservatism and scepticism with regard to 3D visualization, along with the lack of functionality of widely available 3D web browsers, led to the development of a 2D visualization tool with refinements of a number of our imageability features. financial high-dimensional data data visualisation data analysis graphical user interfaces metrics InfoVis Chalmers, M. Brodbeck, D. financial data processing spreadsheet programs 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on data types Lunzer, A. Cotture, P. 2D visualization tool 3D visualizations 3D web browsers Bead visualization system UBS financial institution high-dimensional data layout information visualization system low-dimensional space similarity metrics spreadsheets infovis97--636788 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on Coordinating declarative queries with a direct manipulation data exploration environment. Interactive visualization techniques allow data exploration to be a continuous process, rather than a discrete sequence of queries and results as in traditional database systems. However limitations in expressive power of current visualization systems force users to go outside the system and form a new dataset in order to perform certain operations, such as those involving the relationship among multiple objects. Further, there is no support for integrating data from the new dataset into previous visualizations, so users must recreate them. Visage's information centric paradigm provides an architectural hook for linking data across multiple queries, removing this overhead. This paper describes the addition to Visage of a visual query language, called VQE, which allows users to express more complicated queries than in previous interactive visualization systems. Visualizations can be created from queries and vice versa. When either is updated, the other changes to maintain consistency. data visualisation interactive systems data analysis graphical user interfaces interactive visualization database InfoVis query processing Derthick, M. Roth, S.F. 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on Kolojejchick, J. direct manipulation Visage query languages database management systems visual languagesVQE consistency data exploration environment database systems dataset declarative queries information centric paradigm multiple objects visual query language infovis97--636787 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on Managing multiple focal levels in Table Lens. The Table Lens, focus+context visualization for large data tables, allows users to see 100 times as many data values as a spreadsheet in the same screen space in a manner that enables an extremely immediate form of exploratory data analysis. In the original Table Lens design, data are shown in the context area using graphical representations in a single pixel row. Scaling up the Table Lens technique beyond approximately 500 cases (rows) by 40 variables (columns) requires not showing every value individually and thus raises challenges for preserving the exploratory and navigational ease and power of the original design. We describe two design enhancements for introducing regions of less than a pixel row for each data value and discuss the issues raised by each. pixel data visualisation data analysis user interfaces user interface InfoVis information visualization focus+context focus+context exploratory data analysis 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on very large databases graphical representations Rao, R. Tenev, T. Table Lens context visualization data values design enhancements focus visualization large data tables multiple focal level management screen space single pixel row spreadsheet fisheye Table Lens infovis97--636786 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on Nonlinear magnification fields. We introduce nonlinear magnification fields as an abstract representation of nonlinear magnification, providing methods for converting transformation routines to magnification fields and vice-versa. This new representation provides ease of manipulation and power of expression. By removing the restrictions of explicit foci and allowing precise specification of magnification values, we can achieve magnification effects which were not previously possible. Of particular interest are techniques we introduce for expressing complex and subtle magnification effects through magnification brushing, and allowing intrinsic properties of the data being visualized to create data-driven magnifications. data visualisation user interfaces brushing InfoVis data visualization Keahey, T.A. 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on Robertson, E.L. abstract representation data-driven magnifications explicit foci magnification brushing magnification value specification manipulation nonlinear magnification fields transformation routines infovis97--636785 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on Cacti: a front end for program visualization. We describe a system that allows the user to rapidly construct program visualizations over a variety of data sources. Such a system is a necessary foundation for using visualization as an aid to software understanding. The system supports an arbitrary set of data sources so that information from both static and dynamic analysis can be combined to offer meaningful software visualizations. It provides the user with a visual universal-relation front end that supports the definition of queries over multiple data sources without knowledge of the structure or contents of the sources. It uses a flexible back end with a range of different visualizations, most geared to the efficient display of large amounts of data. The result is a high-quality, easy-to-define program visualization that can address specific problems and hence is useful for software understanding. The overall system is flexible and extensible in that both the underlying data model and the set of visualizations are defined in resource files. data visualisation InfoVis visual programming reverse engineering software tools 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on data model Reiss, S.P. program diagnostics Cacti data sources dynamic analysis high-quality multiple data sources program visualization front end queries resource files software understanding static analysis visual universal-relation front end infovis97--636784 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on On integrating visualization techniques for effective software exploration. This paper describes the SHriMP visualization technique for seamlessly exploring software structure and browsing source code, with a focus on effectively assisting hybrid program comprehension strategies. The technique integrates both pan+zoom and fisheye-view visualization approaches for exploring a nested graph view of software structure. The fisheye-view approach handles multiple focal points, which are necessary when examining several subsystems and their mutual interconnections. Source code is presented by embedding code fragments within the nodes of the nested graph. Finer connections among these fragments are represented by a network that is navigated using a hypertext link-following metaphor. SHriMP combines this hypertext metaphor with animated panning and zooming motions over the nested graph to provide continuous orientation and contextual cues for the user. The SHriMP tool is being evaluated in several user studies. Observations of users performing program understanding tasks with the tool are discussed. zooming network graph data visualisation graphical user interfaces graph theory zoom InfoVis Storey, M. visual programming fisheye reverse engineering zooming software tools visualization techniques 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on hypermedia Fracchia, F.D. Wong, K. Muller, H.A. SHriMP Simple Hierarchical MultiPerspective visualization animated panning fisheye-view visualization hypertext link-following metaphor multiple focal points nested graph view program comprehension program understanding software exploration software structure source code browsing infovis97--636782 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on Managing software with new visual representations. Managing large projects is a very challenging task requiring the tracking and scheduling of many resources. Although new technologies have made it possible to automatically collect data on project resources, it is very difficult to access this data because of its size and lack of structure. We present three novel glyphs for simplifying this process and apply them to visualizing statistics from a multi-million line software project. These glyphs address four important needs in project management: viewing time dependent data; managing large data volumes; dealing with diverse data types; and correspondence of data to real-world concepts. data visualisation statistical analysis statistics Eick, S.G. InfoVis data visualization visual programming Chuah, M.C. visual representations 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on project management scheduling software development management diverse data types large data volume management large project management multi-million line software project project resource tracking statistics time dependent data viewing infovis97--636778 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on Adaptive information visualization based on the user's multiple viewpoints-interactive 3D visualization of the WWW. We introduce the adaptive information visualization method for hypermedia and the WWW based on the user's multiple viewpoints. We propose two graphical interfaces, the CVI and the RF-Cone. The CVI is the interface for interactive viewpoint selection. We can select a viewpoint reflecting our interests by using the CVI. According to the given viewpoint, the RF-Cone adaptively organizes the 3D representation of the hypermedia so that we can understand the semantic and structural relationship of the hypermedia and easily retrieve the information. Combining these methods, we have developed the WWW visualization system which can provide highly efficient navigation. data visualisation graphical user interfaces Internet information retrieval navigation InfoVis human factors 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on World Wide Web hypermedia interactive 3D visualization Teraoka, T. Maruyama, M. interactive systemsCVI RF-Cone adaptive information visualization method interactive viewpoint selection multiple viewpoints semantic relationship structural relationship infovis97--636761 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on A spreadsheet approach to information visualization. In information visualization, as the volume and complexity of the data increases, researchers require more powerful visualization tools that enable them to more effectively explore multidimensional datasets. We discuss the general utility of a novel visualization spreadsheet framework. Just as a numerical spreadsheet enables exploration of numbers, a visualization spreadsheet enables exploration of visual forms of information. We show that the spreadsheet approach facilitates certain information visualization tasks that are more difficult using other approaches. Unlike traditional spreadsheets, which store only simple data elements and formulas in each cell, a visualization spreadsheet cell can hold an entire complex data set, selection criteria, viewing specifications, and other information needed for a full-fledged information visualization. Similarly, inter-cell operations are far more complex, stretching beyond simple arithmetic and string operations to encompass a range of domain-specific operators. We have built two prototype systems that illustrate some of these research issues. The underlying approach in our work allows domain experts to define new data types and data operations, and enables visualization experts to incorporate new visualizations, viewing parameters, and view operations. data visualisation user interfaces information visualization Chi, E.H. InfoVis data structures spreadsheet programs Riedl, J. 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on data types Barry, P. Konstan, J. complex data set data complexity data operations domain-specific operators inter-cell operations multidimensional datasets prototype systems selection criteria spreadsheet approach view operations viewing parameters viewing specifications infovis97--636759 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on Visualizing information on a sphere. We describe a method for the visualization of information units on spherical domains which is employed in the banking industry for risk analysis, stock prediction and other tasks. The system is based on a quantification of the similarity of related objects that governs the parameters of a mass-spring system. Unlike existing approaches we initialize all information units onto the inner surface of two concentric spheres and attach them with springs to the outer sphere. Since the spring stiffnesses correspond to the computed similarity measures, the system converges into an energy minimum which reveals multidimensional relations and adjacencies in terms of spatial neighborhoods. Depending on the application scenario our approach supports different topological arrangements of related objects. In order to cope with large data sets we propose a blobby clustering mechanism that enables encapsulation of similar objects by implicit shapes. In addition, we implemented various interaction techniques allowing semantic analysis of the underlying data sets. Our prototype system IVORY is written in Java, and its versatility is illustrated by an example from financial service providers. interaction financial clustering data visualisation information visualization information visualization InfoVis Java hierarchies object-oriented programming similarity measures Sprenger, T.C. Gross, M.H. IVORY 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on large data sets risk management object-oriented languages Finger, J. bank data processing data encapsulation banking industry blobby clustering mechanism encapsulation energy minimum financial service providers mass-spring system multidimensional relations prototype system risk analysis semantic analysis spatial neighborhood sphere stock prediction topological arrangements physically-based systems multidimensional information space blobby clustering infovis97--636718 10/20/1997 Information Visualization, 1997. (InfoVis '97) proceedings. 1997 IEEE Symposium on H3: laying out large directed graphs in 3D hyperbolic space. We present the H3 layout technique for drawing large directed graphs as node-link diagrams in 3D hyperbolic space. We can lay out much larger structures than can be handled using traditional techniques for drawing general graphs because we assume a hierarchical nature of the data. We impose a hierarchy on the graph by using domain-specific knowledge to find an appropriate spanning tree. Links which are not part of the spanning tree do not influence the layout but can be selectively drawn by user request. The volume of hyperbolic 3-space increases exponentially, as opposed to the familiar geometric increase of euclidean 3-space. We exploit this exponential amount of room by computing the layout according to the hyperbolic metric. We optimize the cone tree layout algorithm for 3D hyperbolic space by placing children on a hemisphere around the cone mouth instead of on its perimeter. Hyperbolic navigation affords a Focus+Context view of the structure with minimal visual clutter. We have successfully laid out hierarchies of over 20,000 nodes. Our implementation accommodates navigation through graphs too large to be rendered interactively by allowing the user to explicitly prune or expand subtrees. graph Munzner, T. data visualisation navigation directed graphs hierarchy hierarchies InfoVis focus+context data visualization trees (mathematics) optimisation graph drawing visual clutter diagrams 1997 Information Visualization, 1997. (InfoVis '97) Proceedings. 1997 IEEE Symposium on 3D hyperbolic space H3 layout technique cone tree layout algorithm domain-specific knowledge euclidean 3-space hierarchical data hyperbolic navigation large directed graphs node-link diagram optimization spanning tree subtree pruning infovis98--729570 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Multi-faceted insight through interoperable visual information analysis paradigms. To gain insight and understanding of complex information collections, users must be able to visualize and explore many facets of the information. The paper presents several novel visual methods from an information analyst's perspective. The authors present a sample scenario, using the various methods to gain a variety of insights from a large information collection. They conclude that no single paradigm or visual method is sufficient for many analytical tasks. Often a suite of integrated methods offers a better analytic environment in today's emerging culture of information overload and rapidly changing issues. They also conclude that the interactions among these visual paradigms are equally as important as, if not more important than, the paradigms themselves insight data visualisation information analysis Thomas, J. information visualization information visualization InfoVis Hetzler, E. information exploration Whitney, P. 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Martucci, L. complex information collections information overload integrated methods interoperable visual information analysis paradigms large information collection multi-faceted insight user scenario information analysis document analysis infovis98--729569 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on BiblioMapper: a cluster-based information visualization technique . The purpose of the paper is to develop a visualization system of a document space, called BiblioMapper, for CISI collections, one of the bibliographic databases available on the Internet. The major function of BiblioMapper is to visualize the document space with a cluster-based visualization technique. The cluster-based visualization technique assembles a set of documents according to semantic similarities. One advantage of this technique is that users are able to focus on and assess each cluster and the documents which the cluster comprises according to their information needs document cluster data visualisation Internet information retrieval visualization InfoVis document image processing 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Song, M. bibliographic systems information needs BiblioMapper CISI collections bibliographic databases cluster-based information visualization technique document space document space visualization semantic similarities information retrieval clustering algorithms textual information infovis98--729568 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on The shape of Shakespeare: visualizing text using implicit surfaces . Information visualization focuses on the use of visual means for exploring non-visual information. While free-form text is a rich, common source of information, visualization of text is a challenging problem since text is inherently non-spatial. The paper explores the use of implicit surface models for visualizing text. The authors describe several techniques for text visualization that aid in understanding document content and document relationships. A simple method is defined for mapping document content to shape. By comparing the shapes of multiple documents, global content similarities and differences may be noted. In addition, they describe a visual clustering method in which documents are arranged in 3D based upon similarity scoring. Documents deemed closely related blend together as a single connected shape. Hence, a document corpus becomes a collection of shapes that reflect inter-document relationships. These techniques provide methods to visualize individual documents as well as corpus meta-data. They then combine the two techniques to produce transparent clusters enclosing individual document shapes. This provides a way to visualize both local and global contextual information. Finally, they elaborate on several potential applications of these methods document text text visualization clustering data visualisation text analysis information retrieval information visualization information visualization Rohrer, R.M. Ebert, D.S. user interface InfoVis text visualization 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on graphics Sibert, J.L. 3D arrangement connected shape corpus meta-data document content document content mapping document corpus document relationships free-form text global content differences global content similarities global contextual information implicit surfaces inter-document relationships local contextual information nonvisual information shape similarity scoring transparent clusters visual clustering method procedural visualization implicit surface modeling blobby models document clustering infovis98--729567 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on LensBar-visualization for browsing and filtering large lists of data. The author proposes a simple and powerful graphical interface tool called the LensBar for filtering and visualizing large lists of data. Browsing and querying are the most important tasks in retrieving information and LensBar integrates the two techniques into a simple scroll window with slider. While it looks familiar to users of conventional graphical interface tools, its filtering and zooming features offer sophisticated handling of large lists of textual data zooming data visualisation graphical user interfaces information retrieval InfoVis browsing 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Masui, T. list processing LensBar filtering features graphical interface tool large data list filtering large data list visualization querying scroll window slide textual data zooming features infovis98--729566 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Comparative visualization of protein structure-sequence alignments . Protein fold recognition (threading) involves the prediction of a protein's three-dimensional shape based on its similarity to a protein whose structure is known. Fold predictions are low resolution; no effort is made to rotate the protein's component amino acid side chains into their correct spatial orientations. Rather, the goal is to recognize the protein family member that most closely resembles the target sequence of unknown structure and to create a sensible alignment of the target to the structure (i.e., a structure-sequence alignment). To complement this structure prediction method the authors have implemented a low resolution molecular graphics tool. Since amino acid side chain orientation is not relevant in fold recognition, amino acid residues are represented by abstract shapes or glyphs much like Lego^TM blocks. They also borrow techniques from comparative streamline visualization to provide clean depictions of the entire protein structure model. By creating a low resolution representation of protein structure, they are able to approximately double the amount of information on the screen. This implementation also possesses the advantage of eliminating distracting and possibly misleading visual clutter resulting from the mapping of protein alignment information onto a high resolution display of a known structure data visualisation biology computing proteins InfoVis 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Pang, A. Hansen, M. Meads, D. molecular biophysics molecular configurations 3D shape prediction abstract shapes amino acid side chain rotation comparative streamline visualization comparative visualization glyphs high resolution display low resolution molecular graphics tool low resolution representation protein alignment information mapping protein fold recognition protein similarity protein structure-sequence alignments spatial orientations target sequence threading proteins structure alignment fold recognition threading similarity glyphs streamlines ribbons amino acids infovis98--729565 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Visualizing decision table classifiers. Decision tables, like decision trees or neural nets, are classification models used for prediction. They are induced by machine learning algorithms. A decision table consists of a hierarchical table in which each entry in a higher level table gets broken down by the values of a pair of additional attributes to form another table. The structure is similar to dimensional stacking. A visualization method is presented that allows a model based on many attributes to be understood even by those unfamiliar with machine learning. Various forms of interaction are used to make this visualization more useful than other static designs interaction machine learning data visualisation data mining InfoVis dimensional stacking learning (artificial intelligence) Becker, B.G. 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on relational data decision tables pattern classification attributes classification models decision table classifier visualization hierarchical table interaction machine learning algorithms prediction classifier decision table dimensional stacking trellis displays infovis98--729564 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Saying it in graphics: from intentions to visualizations. The authors propose a methodology for automatically realizing communicative goals in graphics. It features a task model that mediates the communicative intent and the selection of graphical techniques. The methodology supports the following functions: isolating assertions presentable in graphics; mapping such assertions into tasks for the potential reader, and selecting graphical techniques that support those tasks. They illustrate the methodology by redesigning a textual argument into a multimedia one with the same rhetorical and content structures but employing graphics to achieve some of the intentions data visualisation InfoVis Roth, S.F. 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on multimedia computing visualizations graphics Kerpedjiev, S. Carenini, G. Green, N. Moore, J. assertions automatic communicative goal realization content structures intentions multimedia argument rhetorical structures task model textual argument redesign infovis98--729563 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Geographic visualization: designing manipulable maps for exploring temporally varying georeferenced statistics. Geographic visualization, sometimes called cartographic visualization, is a form of information visualization in which principles from cartography, geographic information systems (GIS), exploratory data analysis (EDA), and information visualization more generally are integrated in the development and assessment of visual methods that facilitate the exploration, analysis, synthesis, and presentation of georeferenced information. The authors report on development and use of one component of a prototype GVis environment designed to facilitate exploration, by domain experts, of time series multivariate georeferenced health statistics. Emphasis is on how manipulable dynamic GVis tools may facilitate visual thinking, pattern noticing, and hypothesis generation. The prototype facilitates the highlighting of data extremes, examination of change in geographic patterns over time, and exploration of similarity among georeferenced variables. A qualitative exploratory analysis of verbal protocols and transaction logs is used to characterize system use. Evidence produced through the characterization highlights differences among experts in data analysis strategies (particularly in relation to the use of attribute ?focusing? combined with time series animation) and corresponding differences in success at noticing spatiotemporal patterns geographic time series data visualisation data analysis information visualization statistics animation MacEachren, A.M. InfoVis time series cartography medical information systems computer animation geographic information systems exploratory data analysis Pickle, L. 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Boscoe, F.P. Haug, D. health care statistical databases cartographic visualization data analysis strategies data extremes experts geographic pattern changes geographic visualization georeferenced information georeferenced variable similarity hypothesis generation manipulable dynamic GVis tools manipulable map design pattern noticing qualitative exploratory analysis spatiotemporal patterns system use temporally varying georeferenced statistics exploration time series multivariate georeferenced health statistics transaction logs verbal protocols visual thinking infovis98--729562 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on IVORY-an object-oriented framework for physics-based information visualization in Java. We present IVORY a newly developed, platform-independent framework for physics based visualization. IVORY is especially designed for information visualization applications and multidimensional graph layout. It is fully implemented in Java 1.1 and its architecture features client server setup, which allows us to run the visualization even on thin clients. In addition, VRML 2.0 exports can be viewed by any VRML plugged-in WWW browser. Individual visual metaphors are invoked into IVORY via an advanced plug-in mechanism, where plug-ins can be implemented by any experienced user. The configuration of IVORY is accomplished using a script language, called IVML. Some interactive visualization examples, such as the integration of a haptic interface illustrate the performance and versatility of our system. Our current implementation supports NT 4.0 graph graph layout data visualisation interactive systems script language InfoVis Java 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on client-server systems Sprenger, T.C. Gross, M.H. IVORY Bielser, D. Strasser, T. physics computing virtual reality languages IVML NT 4 VRML 2 exports VRML plugged-in WWW browser advanced plug-in mechanism client server setup haptic interface information visualization applications interactive visualization examples multidimensional graph layout object oriented framework physics based visualization platform-independent framework thin clients visual metaphors three-dimensional information visualization physics-based graph layout object-oriented visualization toolkit multidimensional information modeling time varying data infovis98--729561 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Algorithm visualization for distributed environments. The paper investigates the visualization of distributed algorithms. We present a conceptual model and a system, VADE, that realizes this model. Since in asynchronous distributed systems there is no way of knowing (let alone, visualizing) the ?real? execution, we show how to generate a visualization which is consistent with the execution of the distributed algorithm. We also present the design and implementation of our system. VADE is designed so that the algorithm runs on the server's machines while the visualization is executed on a Web page on the client's machine. Programmers can write animations quickly and easily with the assistance of VADE's libraries Internet InfoVis Tal, A. computer animation 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on client-server systems Moses, Y. Polunsky, Z. Ulitsky, L. distributed algorithms program visualisationVADE Web page algorithm visualization animations asynchronous distributed systems client machine conceptual model distributed environments server machines infovis98--729560 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on An operator interaction framework for visualization systems. Information visualization encounters a wide variety of different data domains. The visualization community has developed representation methods and interactive techniques. As a community, we have realized that the requirements in each domain are often dramatically different. In order to easily apply existing methods, researchers have developed a semiology of graphic representations. We have extended this research into a framework that includes operators and interactions in visualization systems, such as a visualization spreadsheet. We discuss properties of this framework and use it to characterize operations spanning a variety of different visualization techniques. The framework developed in the paper enables a new way of exploring and evaluating the design space of visualization operators, and helps end users in their analysis tasks interaction data visualisation interactive systems user interfaces information visualization information visualization design Chi, E.H. InfoVis framework human factors visualization systems 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on visualization techniques interactive techniques spreadsheet programs Riedl, J. analysis tasks data domains design space end users graphic representations operator interaction framework representation methods visualization community visualization operators visualization spreadsheet visualization systems operators user interaction view/value spreadsheet extensibility infovis98--729559 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Similarity clustering of dimensions for an enhanced visualization of multidimensional data. The order and arrangement of dimensions (variates) is crucial for the effectiveness of a large number of visualization techniques such as parallel coordinates, scatterplots, recursive pattern, and many others. We describe a systematic approach to arrange the dimensions according to their similarity. The basic idea is to rearrange the data dimensions such that dimensions showing a similar behavior are positioned next to each other. For the similarity clustering of dimensions, we need to define similarity measures which determine the partial or global similarity of dimensions. We then consider the problem of finding an optimal one- or two-dimensional arrangement of the dimensions based on their similarity. Theoretical considerations show that both, the one- and the two-dimensional arrangement problem are surprisingly hard problems, i.e. they are NP complete. Our solution of the problem is therefore based on heuristic algorithms. An empirical evaluation using a number of different visualization techniques shows the high impact of our similarity clustering of dimensions on the visualization results Keim, D.A. evaluation clustering parallel coordinates data visualisation data mining parallel coordinates InfoVis computational complexity multidimensional data scatterplot 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on visualization techniques similarity measures Ankerst, M. Berchtold, S. NP complete data dimensions enhanced visualization global similarity hard problems heuristic algorithms recursive pattern similar behavior similarity clustering systematic approach two dimensional arrangement infovis98--729558 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on The generalized detail in-context problem. The paper describes a general formulation of the ?detail-in-context? problem, which is a central issue of fundamental importance to a wide variety of nonlinear magnification systems. A number of tools are described for dealing with this problem effectively. These tools can be applied to any continuous nonlinear magnification system, and are not tied to specific implementation features of the system that produced the original transformation. Of particular interest is the development of ?seamless multi level views?, which allow multiple global views of an information space (each having different information content) to be integrated into a single view without discontinuity data visualisation interactive systems user interfaces InfoVis Keahey, T.A. 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on continuous nonlinear magnification system general formulation generalized detail in-context problem information content information space multiple global views nonlinear magnification systems seamless multi level views infovis98--729557 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Dynamic aggregation with circular visual designs. One very effective method for managing large data sets is aggregation or binning. We consider two aggregation methods that are tightly coupled with interactive manipulation and the visual representation of the data. Through this integration we hope to provide effective support for the aggregation process, specifically by enabling: 1) automatic aggregation, 2) continuous change and control of the aggregation level, 3) spatially based aggregates, 4) context maintenance across different aggregate levels, and 5) feedback on the level of aggregation data visualisation interactive systems user interfaces visual representation InfoVis Chuah, M.C. 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on spatial data structures aggregate levels aggregation level control aggregation methods aggregation process automatic aggregation binning circular visual designs context maintenance continuous change dynamic aggregation feedback interactive manipulation large data set management spatially based aggregates infovis98--729556 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on An interactive view for hierarchical clustering. The paper describes a visualization of a general hierarchical clustering algorithm that allows the user to manipulate the number of classes produced by the clustering method without requiring a radical re-drawing of the clustering tree. The visual method used, a space filling recursive division of a rectangular area, keeps the items under consideration at the same screen position, even while the number of classes is under interactive control. As well as presenting a compact representation of the clustering with different cluster numbers, this method is particularly useful in a linked views environment where additional information can be added to a display to encode other information, without this added level of detail being perturbed when changes are made to the number of clusters cluster clustering interactive systems pattern clustering data analysis visualization InfoVis hierarchical clustering program visualisation 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Wills, G.J. cluster numbers clustering method clustering tree compact representation interactive control interactive view linked views environment radical re-drawing rectangular area space filling recursive division visual method infovis98--729555 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Reconfigurable disc trees for visualizing large hierarchical information space. We present a new visualization technique, called RDT (Reconfigurable Disc Tree) which can alleviate the disadvantages of cone trees significantly for large hierarchies while maintaining its context of using 3D depth. In RDT, each node is associated with a disc, around which its children are placed. Using discs instead of cones as the basic shape in RDT has several advantages: significant reduction of occluded region, sharp increase in number of displayed nodes, and easy projection onto plane without visual overlapping. We show that RDT can greatly enhance user perception by transforming its shapes dynamically in several ways: (1) disc tree which can significantly reduce the occluded region by the foreground objects; (2) compact disc tree which can increase the number of nodes displayed on the screen; and (3) plane disc tree which can be mapped onto the plane without visual overlapping. We describe an implementation of our visualization system called VISIT (Visual Information System for reconfigurable dIsc tree). It provides 2D and 3D layouts for RDT and various user interface features such as tree reconfiguration, tree transformation, tree shading, viewing transformation, animation, selection and browsing which can enhance the user perception and navigation capabilities. We also evaluate our system using the following three metrics: percentage of occlusion, density of displayed nodes on a screen, and number of identifiable nodes data visualisation user interfaces metrics navigation perception animation hierarchies InfoVis information visualization visualization technique trees (mathematics) occlusion visualization system tree data structures hierarchy browsing 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on cone trees Pang, A. Jeong, C.-S. 2D layouts 3D depth 3D layouts RDT Reconfigurable Disc Tree VISIT Visual Information System for reconfigurable dIsc tree animation children compact disc tree displayed nodes foreground objects large hierarchical information space visualization large hierarchies occluded region plane disc tree reconfigurable disc trees tree reconfiguration tree shading tree transformation user interface features user navigation capabilities user perception viewing transformation visual overlapping disc tree compact disc tree plane disc tree infovis98--729554 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Traversal-based visualization of data structures. Algorithm animation systems and graphical debuggers perform the task of translating program state into visual representations. While algorithm animations typically rely on user augmented source code to produce visualizations, debuggers make use of symbolic information in the target program. As a result, visualizations produced by debuggers often lack important semantic content, making them inferior to algorithm animation systems. The paper presents a method to provide higher level, more informative visualizations in a debugger using a technique called traversal based visualization. The debugger traverses a data structure using a set of user supplied patterns to identify parts of the data structure to be drawn a similar way. A declarative language is used to specify the patterns and the actions to take when the patterns are encountered. Alternatively, the user can construct traversal specifications through a graphical user interface to the declarative language. Furthermore, the debugger supports modification of data. Changes made to the on-screen representation are reflected in the underlying data graphical user interfaces graphical user interface animation InfoVis data structures program visualisation computer animation Korn, J. 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on visual representations Appel, A.W. formal specification high level languages program debugging algorithm animation systems algorithm animations data structure visualization declarative language graphical debuggers informative visualizations on-screen representation program state semantic content symbolic information traversal based visualization traversal specifications user augmented source code user supplied patterns infovis98--729553 10/19/1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on WEBPATH-a three dimensional Web history. A number of usability studies report that many users of the WWW cannot find pages already visited, additionally many users cannot visualise where they are, or where they have been browsing. Currently, readily available WWW browsers provide history mechanisms that offer little or no support in the presentation and manipulation of visited sites. Manipulation and presentation of usage data, such as a browse history has been used in a number of cases to aid users in searching for previously attained data, and to teach or assist other users in their browse or searching techniques. The paper presents a virtual reality (VR) based application to be used alongside traditional Web browsers, which provides them with a flexibly tailorable real time visualisation of their history usability data visualisation Internet information retrieval history InfoVis Smith, G. browsing online front-ends virtual reality real-time systems 1998 Information Visualization, 1998. (InfoVis '98) Proceedings. 1998 IEEE Symposium on Frecon, E. WEBPATH WWW browsers WWW users browse history history mechanisms searching techniques tailorable real time visualisation three dimensional Web history traditional Web browsers usability studies virtual reality based application virtual environments World Wide Web visualization web browsing infovis99--801851 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Cluster and calendar based visualization of time series data. A new method is presented to get an insight into univariate time series data. The problem addressed is how to identify patterns and trends on multiple time scales (days, weeks, seasons) simultaneously. The solution presented is to cluster similar daily data patterns, and to visualize the average patterns as graphs and the corresponding days on a calendar. This presentation provides a quick insight into both standard and exceptional patterns. Furthermore, it is well suited to interactive exploration. Two applications, numbers of employees present and energy consumption, are presented insight time series cluster InfoVis van Wijk, J.J. 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Van Selow, E.R. infovis99--801852 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Visualizing application behavior on superscalar processors. The advent of superscalar processors with out-of-order execution makes it increasingly difficult to determine how well an application is utilizing the processor and how to adapt the application to improve its performance. We describe a visualization system for the analysis of application behavior on superscalar processors. Our system provides an overview-plus-detail display of the application's execution. A timeline view of pipeline performance data shows the overall utilization of the pipeline. This information is displayed using multiple time scales, enabling the user to drill down from a high-level application overview to a focus region of hundreds of cycles. This region of interest is displayed in detail using an animated cycle-by-cycle view of the execution. This view shows how instructions are reordered and executed and how functional units are being utilized. Additional context views correlate instuctions in this detailed view with the relevant source code for the application. This allows the user to discover the root cause of the poor pipeline utilization and make changes to the application to improve its performance. This visualization system can be easily configured to display a variety of processor models and configurations. We demonstrate it for both the MXS and MMIX processor models overview Hanrahan, P. InfoVis Stolte, C. 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on visualization systems Bosch, R. Rosenblum, M. computer systems visualization superscalar processors infovis99--801853 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Sensemaking of evolving Web sites using visualization spreadsheets. In the process of knowledge discovery, workers examine available information in order to make sense of it. By sensemaking, we mean interacting with and operating on the information with a variety of information processing mechanisms. Previously, we introduced a concept that uses the spreadsheet metaphor with cells containing visualizations of complex data. We extend and apply a cognitive model called ¡°visual sensemaking¡± to the visualization spreadsheet. We use the task of making sense of a large Web site as a concrete example throughout the paper for demonstration. Using a variety of visualization techniques, such as the Disk Tree and Cone Tree, we show that the interactions of the visualization spreadsheet help users draw conclusions from the overall relationships of the entire information set sensemaking sensemaking Card, S.K. Chi, E.H. InfoVis World Wide Web information visualization 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on spreadsheet information ecologies log file analysis infovis99--801854 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Does animation help users build mental maps of spatial information? We examine how animating a viewpoint change in a spatial information system affects a user's ability to build a mental map of the information in the space. We found that animation improves users' ability to reconstruct the information space, with no penalty on task performance time. We believe that this study provides strong evidence for adding animated transitions in many applications with fixed spatial data where the user navigates around the data space animation Bederson, B.B. InfoVis 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Boltman, A. infovis99--801855 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Evaluating a visualisation of image similarity as a tool for image browsing. A similarity metric based on the low-level content of images can be used to create a visualisation in which visually similar images are displayed close to each other. We are carrying out a series of experiments to evaluate the usefulness of this type of visualisation as an image browsing aid. The initial experiment, described, considered whether people would find a given photograph more quickly in a visualisation than in a randomly arranged grid of images. The results show that the subjects were faster with the visualisation, although in post-experiment interviews many of them said that they preferred the clarity and regularity of the grid. We describe an algorithm with which the best aspects of the two layout types can be combined experiment InfoVis 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Rodden, K. Basalaj, W. Sinclair, D. Wood, K. infovis99--801856 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Domain analysis: a technique to design a user-centered visualization framework. Domain Analysis for Data Visualization (DADV) is a technique to use when investigating a domain where data visualizations are going to be designed and added to existing software systems. DADV was used to design the data visualization in VisEIO-LCA, which is a framework to visualize environmental data about products. Most of the visualizations are designed using the following stages: formatting data in tables, selecting visual structures, and rendering the data on the screen. Although many visualization authors perform implicit domain analysis, in this paper domain analysis is added explicitly to the process of designing visualizations with the goal of producing move usable software tools. Environmental Life-Cycle Assessment (LCA) is used as a test bed for this technique InfoVis 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Espinosa, O.J. Hendrickson, C. Garrett, J.H., Jr. infovis99--801857 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on A framework for focus+context visualization. This paper aims to give a systematic account of focus+context visualization techniques, i.e. visualizations which aim to give users integrated visual access to details and context in a data set. We introduce the notion that there are different orders of information visualization with focus+context being a second-order visualization and provide a formal framework for describing and constructing focus+context visualizations InfoVis focus+context Holmquist, L.E. Bjork, S. Redstrom, J. 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on infovis99--801858 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Navigating hierarchies with structure-based brushes. Interactive selection is a critical component in exploratory visualization, allowing users to isolate subsets of the displayed information for highlighting, deleting, analysis, or focussed investigation. Brushing, a popular method for implementing the selection process, has traditionally been performed in either screen space or data space. We introduce the concept of a structure-based brush, which can be used to perform selection in hierarchically structured data sets. Our structure-based brush allows users to navigate hierarchies by specifying focal extents and level-of-detail on a visual representation of the structure. Proximity-based coloring, which maps similar colors to data that are closely related within the structure, helps convey both structural relationships and anomalies. We describe the design and implementation of our structure-based brushing tool. We also validate its usefulness using two distinct hierarchical visualization techniques, namely hierarchical parallel coordinates and tree-maps parallel coordinates Ward, M.O. Rundensteiner, E.A. brushing hierarchies InfoVis exploratory data analysis 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Fua, Y.-H. brushing hierarchical representation interactive selection infovis99--801859 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Dynamic hierarchy specification and visualization. This paper describes concepts that underlie the design and implementation of an information exploration system that allows users to impose arbitrary hierarchical organizations on their data. Such hierarchies allow a user to embed important semantic information into the hierarchy definition. Our goal is to recognize the significance of this implicit information and to utilize it in the hierarchy visualization. The innovative features of our system include the dynamic modification of the hierarchy definitions and the definition and implementation of a set of layout algorithms that utilize semantic information implicit in the tree construction hierarchy hierarchies InfoVis 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Bergeron, R.D. Wilson, R.M. infovis99--801860 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Cushion treemaps: visualization of hierarchical information. A new method is presented for the visualization of hierarchical information, such as directory structures and organization structures. Cushion treemaps inherit the elegance of standard treemaps: compact, space-filling displays of hierarchical information, based on recursive subdivision of a rectangular image space. Intuitive shading is used to provide insight in the hierarchical structure. During the subdivision, ridges are added per rectangle, which are rendered with a simple shading model. The result is a surface that consists of recursive cushions. The method is efficient, effective, easy to use and implement, and has a wide applicability insight InfoVis van Wijk, J.J. van de Wetering, H. 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on infovis99--801861 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on 3D interactive visualization for inter-cell dependencies of spreadsheets. This paper proposes a new technique to visualize dependencies among cells in a spreadsheet. In this way, the system firstly visualizes a spreadsheet on a plane in three-dimensional space, and draws arcs between interrelated cells. By allowing a user to select an arbitrary cell and lift it up with direct manipulation, the system utilizes the third dimension to ameliorate visual occlusion of crossing arcs. As the user lifts a focused cell up, the interrelated cells are lifted up together; thus hidden dataflow networks can be visually intelligible interactively. Because spreadsheets are aimed at calculation itself rather than appearances of outputs, their mechanism is relatively invisible and not obvious for ordinary users. Our visualization helps such users to understand structures and mechanism of spreadsheets information visualization InfoVis occlusion 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Shiozawa, H. Okada, K. Matsushita, Y. 3D user interface spreadsheet inter-cell dependencies lifting-up operation Natto View infovis99--801862 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Efficient multi-object dynamic query histograms. Dynamic queries offer continuous feedback during range queries, and have been shown to be effective and satisfying. Recent work has extended them to datasets of 100,000 objects and, separately, to queries involving relations among multiple objects. The latter work enables filtering houses by properties of their owners, for instance. Our primary concern is providing feedback from histograms during dynamic query. The height of each histogram bar shows the count of selected objects whose attribute value falls into a given range. Unfortunately, previous efficient algorithms for single object queries overcount in the case of multiple objects if for instance, a house has multiple owners. This paper presents an efficient algorithm that with high probability closely approximates the true counts dynamic query InfoVis Derthick, M. 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Roth, S.F. Harrison, J. Moore, A. infovis99--801863 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Aggregate Towers: scale sensitive visualization and decluttering of geospatial data. We have developed a technique, Aggregate Towers, that allows geospatial data to be visualized across a range of map scales. We use a combination of data aggregation algorithms and dynamically aggregating data markers (e.g., icons or symbols) to accommodate interactive zooming by a user while maintaining a representation that remains intuitive, consistent across multiple scales and uncluttered. This approach implicitly generates multiple levels of overview displays from a single set of underlying data zooming overview geospatial information visualization InfoVis data visualization zoom 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Rayson, J.K. aggregation cartography infovis99--801864 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on VisageWeb: visualizing WWW data in Visage. VisageWeb is an information-centric user interface to the World Wide Web built within the Visage data visualization environment. This paper traces the development of the VisageWeb project, using it to motivate an exploration of how an information-centric architecture copes with new visualization challenges. We conclude with a presentation of the VisageWeb prototype itself information visualization InfoVis World Wide Web world wide web 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Lucas, P. user interface Higgins, M. Sean, J. infovis99--801865 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on The automated multidimensional detective. Automation has arrived to parallel coordinates. A geometrically motivated classifier is presented and applied, with both training and testing stages, to 3 real datasets. Our results compared to those from 33 other classifiers have the least error. The algorithm is based on parallel coordinates and has very low computational complexity in the number of variables and the size of the dataset-contrasted with the very high or unknown (often unstated) complexity of other classifiers, the low complexity enables the rule derivation to be done in near real-time hence making the classification adaptive to changing conditions, provides comprehensible and explicit rules-contrasted to neural networks which are ¡°black boxes¡±, does dimensionality selection-where the minimal set of original variables (not transformed new variables as in Principal Component Analysis) required to state the rule is found, orders these variables so as to optimize the clarity of separation between the designated set and its complement-this solves the pesky ¡°ordering problem¡± in parallel coordinates. The algorithm is display independent, hence it can be applied to very large in size and number of variables datasets. Though it is instructive to present the results visually, the input size is no longer display-limited as for visual data mining parallel coordinates data mining InfoVis 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Inselberg, A. Avidan, T. infovis99--801866 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Visualizing association rules for text mining. An association rule in data mining is an implication of the form X¡æY where X is a set of antecedent items and Y is the consequent item. For years researchers have developed many tools to visualize association rules. However, few of these tools can handle more than dozens of rules, and none of them can effectively manage rules with multiple antecedents. Thus, it is extremely difficult to visualize and understand the association information of a large data set even when all the rules are available. This paper presents a novel visualization technique to tackle many of these problems. We apply the technology to a text mining study on large corpora. The results indicate that our design can easily handle hundreds of multiple antecedent association rules in a three-dimensional display with minimum human interaction, low occlusion percentage, and no screen swapping interaction text Thomas, J. Wong, P.C. data mining InfoVis occlusion 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Whitney, P. infovis99--801867 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on A Java-based visual mining infrastructure and applications. Many real-world KDD (Knowledge Discovery & Data Mining) applications involve the navigation of large volumes of information on the web, such as, Internet resources, hot topics, and telecom phone switches. Quite often users feel lost, confused and overwhelmed with displays that contain too much information. This paper discusses a new content-driven visual mining infrastructure called VisMine, that uses several innovative techniques: (1) hidden visual structure and relationships for uncluttering displays; (2) simultaneous visual presentations for high-dimensional knowledge discovery; and (3) a new visual interface to plug in existing graphic toolkits for expanding its use in a wide variety of visual applications. We have applied this infrastructure to three data mining visualization applications-topic hierarchy for document navigation, web-based trouble shooting, and telecom switch mining document navigation Hao, M.C. Dayal, U. data mining hierarchy InfoVis Hsu, M. 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Baker, J. D'Eletto, R. infovis99--801868 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on The sunflower visual metaphor, a new paradigm for dimensional compression. This paper introduces the Sunflower visual metaphor for information visualization. The visual metaphor is presented as an alternative to current techniques of dimensional compression and the visualization tools that employ them. The paper discusses the motivation for the Sunflower paradigm, its implementation and critical factors for producing an effective visualization. A primary driver in this research effort has been to develop a visualization tool that facilitates browsing, knowledge discovery, and that supports learning through sense making and integration of new information visualization text visualization information retrieval Rose, S. information visualization InfoVis knowledge management 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on infovis99--801869 10/24/1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Constellation: a visualization tool for linguistic queries from MindNet. Constellation is a visualization system for the results of queries from the MindNet natural language semantic network. Constellation is targeted at helping MindNet's creators and users refine their algorithms, as opposed to understanding the structure of language. We designed a special-purpose graph layout algorithm which exploits higher-level structure in addition to the basic node and edge connectivity. Our layout prioritizes the creation of a semantic space to encode plausibility instead of traditional graph drawing metrics like minimizing edge crossings. We make careful use of several perceptual channels both to minimize the visual impact of edge crossings and to emphasize highlighted constellations of nodes and edges network graph graph layout Munzner, T. metrics Robertson, G. InfoVis graph drawing 1999 Information Visualization, 1999. (Info Vis '99) Proceedings. 1999 IEEE Symposium on Guimbretiere, F. infovis00--885101 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on New methods for the visualization of electric power system information. One area in need of new research in information visualization is the operation and analysis of large-scale electric power systems. In analyzing power systems, one is usually confronted with a large amount of multivariate data. With systems containing tens of thousands of electrical nodes (buses), a key challenge is to present this data in a form so the user can assess the state of the system in an intuitive and quick manner. This is particularly true when trying to analyze relationships between actual network power flows, the scheduled power flows, and the capacity of the transmission system. With electric industry restructuring and the move towards having a single entity, such as an independent system operator or pool, operate a much larger system, this need has become more acute. This paper presents several power system visualization techniques to help in this task. These techniques include animation of power system flow values, contouring of bus and transmission line flow values, data aggregation techniques and interactive 3D data visualization network animation InfoVis 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Overbye, T.J. Weber, J.D. infovis00--885102 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Collaborative geographic visualization: enabling shared understanding of environmental processes. We describe a prototype same-time/different-place collaborative geovisualization environment. We outline an approach to understanding use and usability and present results of interviews with domain experts about the ways in which collaborative visualization might enable groups to work at a distance. One goal for our research is to design an effective and flexible system that can support group work on environmental science research mediated through dynamic geovisualization displays. We are addressing this goal using a four-step human-centered system design process, modeled on that proposed by (Gabbard et al., 1999) for development and evaluation of virtual environments. The steps they delineate are: user task analysis; expert guideline-based evaluation; formative user-centered evaluation; and summative comparative evaluation geographic evaluation usability MacEachren, A.M. InfoVis geovisualization 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Brewer, I. Abdo, H. Gundrum, J. Otto, G. infovis00--885103 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Interactive problem solving via algorithm visualization. COMIND is a tool for conceptual design of industrial products. It helps designers define and evaluate the initial design space by using search algorithms to generate sets of feasible solutions. Two algorithm visualization techniques, Kaleidoscope and Lattice, and one visualization of n-dimensional data, MAP, are used to externalize the machine's problem solving strategies and the tradeoffs as a result of using these strategies. After a short training period, users are able to discover tactics to explore design space effectively, evaluate new design solutions, and learn important relationships among design criteria, search speed and solution quality. We thus propose that visualization can serve as a tool for interactive intelligence, ie., human-machine collaboration for solving complex problems collaboration Lalanne, D. InfoVis 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Pu, P. infovis00--885104 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Metaphor-aware 3D navigation. Anyone who has ever experienced three-dimensional (3D) interfaces will agree that navigating in a 3D world is not a trivial task. The user interface of traditional 3D browsers provides simple navigation tools that allow the user to modify the camera parameters such as orientation, position and focal. Using these tools, it is frequent that, after some movements, the user is lost in the virtual 3D space and usually tries to restart from the beginning. We present how the 3D navigation problem is addressed in the context of the CyberNet project (Abel et al., 2000). Our underlying principle is to help the user navigate by adapting the navigation tool to the virtual world. We feel that the navigation schemes provided by the 3D browsers are too generic for some specific 3D tools and we have developed adaptive navigation features that are dependent on the 3D metaphor used for visualizing the information and on the user's task navigation InfoVis 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Russo dos Santos, C. Gros, P. Abel, P. Loisel, D. Trichaud, N. Paris, J.P. infovis00--885105 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Creativity, complexity, and precision: information visualization for (landscape) architecture. Drawing on ethnographic studies of (landscape) architects at work, this paper presents a human-centered approach to information visualization. A 3D collaborative electronic workspace allows people to configure, save and browse arrangements of heterogeneous work materials. Spatial arrangements and links are created and maintained as an integral part of ongoing work with `live' documents and objects. The result is an extension of the physical information space of the architects' studio that utilizes the potential of electronic data storage, visualization and network technologies to support work with information in context context network InfoVis information visualization 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Buscher, M. Shapiro, D. Christensen, M. Mogensen, P. Orbaek, P. architecture work materials spatio-temporal order electronic workspace infovis00--885086 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Polaris: a system for query, analysis and visualization of multi-dimensional relational databases. In the last several years, large multi-dimensional databases have become common in a variety of applications such as data warehousing and scientific computing. Analysis and exploration tasks place significant demands on the interfaces to these databases. Because of the size of the data sets, dense graphical representations are more effective for exploration than spreadsheets and charts. Furthermore, because of the exploratory nature of the analysis, it must be possible for the analysts to change visualizations rapidly as they pursue a cycle involving first hypothesis and then experimentation. The authors present Polaris, an interface for exploring large multi-dimensional databases that extends the well-known Pivot Table interface. The novel features of Polaris include an interface for constructing visual specifications of table based graphical displays and the ability to generate a precise set of relational queries from the visual specifications. The visual specifications can be rapidly and incrementally developed, giving the analyst visual feedback as they construct complex queries and visualizations Hanrahan, P. InfoVis Stolte, C. 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on infovis00--885087 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Getting portals to behave. Data visualization environments help users understand and analyze their data by permitting interactive browsing of graphical representations of the data. To further facilitate understanding and analysis, many visualization environments have special features known as portals, which are sub-windows of a data canvas. Portals provide a way to display multiple graphical representations simultaneously, in a nested fashion. This makes portals an extremely powerful and flexible paradigm for data visualization. Unfortunately, with this flexibility comes complexity. There are over a hundred possible ways each portal can be configured to exhibit different behaviors. Many of these behaviors are confusing and certain behaviors can be inappropriate for a particular setting. It is desirable to eliminate confusing and inappropriate behaviors. The authors construct a taxonomy of portal behaviors and give recommendations to help designers of visualization systems decide which behaviors are intuitive and appropriate for a particular setting. They apply these recommendations to an example setting that is fully visually programmable and analyze the resulting reduced set of behaviors. Finally, the authors consider a real visualization environment and demonstrate some problems associated with behaviors that do not follow their recommendations taxonomy InfoVis data visualization Olston, C. 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Woodruff, A. portals multiple views infovis00--885088 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on A scalable framework for information visualization. The paper describes major concepts of a scalable information visualization framework. We assume that the exploration of heterogeneous information spaces at arbitrary levels of detail requires a suitable preprocessing of information quantities, the combination of different graphical interfaces and the illustration of the frame of reference of given information sets. The innovative features of our system include: dynamic hierarchy computation and user controlled refinement of those hierarchies for preprocessing unstructured information spaces; a new Focus+Context technique for visualizing complex hierarchy graphs; a new paradigm for visualizing information structures within their frame of reference; and a new graphical interface that utilizes textual similarities to arrange objects of high dimensional information space in 3-dimensional visualization space hierarchy hierarchies InfoVis focus+context Schumann, H. Kreuseler, M. 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Lopez, N. infovis00--885089 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Visualizing massive multi-digraphs. We describe MGV, an integrated visualization and exploration system for massive multi-digraph navigation. MGV's only assumption is that the vertex set of the underlying digraph corresponds to the set of leaves of a predetermined tree T. MGV builds an out-of-core graph hierarchy and provides mechanisms to plug in arbitrary visual representations for each graph hierarchy slice. Navigation from one level to another of the hierarchy corresponds to the implementation of a drill-down interface. In order to provide the user with navigation control and interactive response, MGV incorporates a number of visualization techniques like interactive pixel-oriented 2D and 3D maps, statistical displays, multi-linked views, and a zoomable label based interface. This makes the association of geographic information and graph data very natural. MGV follows the client-server paradigm and it is implemented in C and Java-3D. We highlight the main algorithmic and visualization techniques behind the tools and point out along the way several possible application scenarios. Our techniques are being applied to multi-graphs defined on vertex sets with sizes ranging from 100 million to 250 million vertices visualization geographic graph pixel navigation hierarchy InfoVis hierarchies Abello, J. graphs Korn, J. massive data sets 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on out-of-core algorithms infovis00--885090 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Density functions for visual attributes and effective partitioning in graph visualization. Two tasks in graph visualization require partitioning: the assignment of visual attributes and divisive clustering. Often, we would like to assign a color or other visual attributes to a node or edge that indicates an associated value. In an application involving divisive clustering, we would like to partition the graph into subsets of graph elements based on metric values in such a way that all subsets are evenly populated. Assuming a uniform distribution of metric values during either partitioning or coloring can have undesired effects such as empty clusters or only one level of emphasis for the entire graph. Probability density functions derived from statistics about a metric can help systems succeed at these tasks graph clustering clustering statistics metrics InfoVis color graph visualization Melancon, G. 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Herman, I. Marshall, M.S. graph navigation infovis00--885091 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Focus+context display and navigation techniques for enhancing radial, space-filling hierarchy visualizations. Radial, space-filling visualizations can be useful for depicting information hierarchies, but they suffer from one major problem. As the hierarchy grows in size, many items become small, peripheral slices that are difficult to distinguish. We have developed three visualization/interaction techniques that provide flexible browsing of the display. The techniques allow viewers to examine the small items in detail while providing context within the entire information hierarchy. Additionally, smooth transitions between views help users maintain orientation within the complete information space interaction Stasko, J. navigation radial hierarchy hierarchies InfoVis Zhang, E. focus+context 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on infovis00--885092 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on A taxonomy of visualization techniques using the data state reference model. In previous work, researchers have attempted to construct taxonomies of information visualization techniques by examining the data domains that are compatible with these techniques. This is useful because implementers can quickly identify various techniques that can be applied to their domain of interest. However, these taxonomies do not help the implementers understand how to apply and implement these techniques. The author extends and proposes a new way to taxonomize information visualization techniques by using the Data State Model (E.H. Chi and J.T. Reidl, 1998). In fact, as the taxonomic analysis in the paper will show, many of the techniques share similar operating steps that can easily be reused. The paper shows that the Data State Model not only helps researchers understand the space of design, but also helps implementers understand how information visualization techniques can be applied more broadly information visualization taxonomy Chi, E.H. InfoVis 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on data state model reference model taxonomy techniques operators infovis00--885093 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on GADGET/IV: a taxonomic approach to semi-automatic design of information visualization applications using modular visualization environment. Since novice users of visualization systems lack knowledge and expertise in data visualization, it is a tough task for them to generate efficient and effective visualizations that allow them to comprehend information that is embedded in the data. Therefore, systems supporting the users to design appropriate visualizations are of great importance. The GADGET (Goal-oriented Application Design Guidance for modular visualization EnvironmenTs) system, which has been developed by the authors (1997), interactively helps users to design scientific visualization applications by presenting appropriate MVE (Modular Visualization Environment) prototypes according to the specification of the visualization goals expressed mainly with the Wehrend matrix (S. Wehrend & C. Lewis, 1990). This paper extends this approach in order to develop a system named GADGET/IV, which is intended to provide the users with an environment for semi-automatic design of information visualization (IV) applications. To this end, a novel goal-oriented taxonomy of IV techniques is presented. Also, an initial design of the system architecture and user assistance flow is described. The usefulness of the GADGET/IV system is illustrated with example problems of Web site access frequency analysis matrix taxonomy InfoVis 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Fujishiro, I. Ichikawa, Y. Furuhata, R. Takeshima, Y. infovis00--885094 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Redefining the focus and context of focus+context visualization. The increasing diversity of computers, especially among small mobile devices such as mobile phones and PDAs, raise new questions about information visualization techniques developed for the desktop computer. Using a series of examples ranging from applications for ordinary desktop displays to web-browsers and other applications for PDAs, we describe how a focus+context technique, Flip Zooming, is changed due to the situation it is used in. Based on these examples, we discuss how the use of ¡°focus¡± and ¡°context¡± in focus+context techniques change in order to fit new areas of use for information visualization zooming InfoVis focus+context 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Bjork, S. Redstrom, J. infovis00--885095 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on From metaphor to method: cartographic perspectives on information visualization. By virtue of their spatio-cognitive abilities, humans are able to navigate through geographic space as well as meaningfully communicate geographic information represented in cartographic form. The current dominance of spatial metaphors in information visualization research is the result of the realization that those cognitive skills also have value in the exploration and analysis of non-geographic information. While mapping or landscape metaphors are routinely used in this field, there is a noticeable lack of consideration for existing cartographic expertise. This is especially apparent whenever problematic issues are encountered, such as graphic complexity or feature labeling. There are a number of areas in which a cartographic outlook could provide a valuable perspective. This paper discusses how geographic and cartographic notions may influence the design of visualizations for textual information spaces. Map projections, generalization, feature labeling and map design issues are discussed geographic InfoVis 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Skupin, A. infovis00--885096 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Information content measures of visual displays. With an increase in the number of different visualization techniques, it becomes necessary to develop a measure for evaluating the effectiveness of visualizations. Metrics to evaluate visual displays were developed based on measures of information content developed by Shannon and used in communication theory. These measures of information content can be used to quantify the relative effectiveness of displays metrics theory InfoVis 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Yang-Pelaez, J. Flowers, W.C. infovis00--885097 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Visualizing sequential patterns for text mining. A sequential pattern in data mining is a finite series of elements such as A¡æB¡æC¡æD where A, B, C, and D are elements of the same domain. The mining of sequential patterns is designed to find patterns of discrete events that frequently happen in the same arrangement along a timeline. Like association and clustering, the mining of sequential patterns is among the most popular knowledge discovery techniques that apply statistical measures to extract useful information from large datasets. As out computers become more powerful, we are able to mine bigger datasets and obtain hundreds of thousands of sequential patterns in full detail. With this vast amount of data, we argue that neither data mining nor visualization by itself can manage the information and reflect the knowledge effectively. Subsequently, we apply visualization to augment data mining in a study of sequential patterns in large text corpora. The result shows that we can learn more and more quickly in an integrated visual data-mining environment text clustering Cowley, W. Thomas, J. Wong, P.C. Foote, H. data mining InfoVis Jurrus, E. 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on infovis00--885098 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on ThemeRiver: visualizing theme changes over time. ThemeRiverTM is a prototype system that visualizes thematic variations over time within a large collection of documents. The ¡°river¡± flows from left to right through time, changing width to depict changes in thematic strength of temporally associated documents. Colored ¡°currents¡± flowing within the river narrow or widen to indicate decreases or increases in the strength of an individual topic or a group of topics in the associated documents. The river is shown within the context of a timeline and a corresponding textual presentation of external events InfoVis timeline Hetzler, E. Nowell, L. Havre, S. 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on visualization metaphors trend analysis infovis00--885099 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Lighthouse: showing the way to relevant information. Lighthouse is an on-line interface for a Web-based information retrieval system. It accepts queries from a user, collects the retrieved documents from the search engine, organizes and presents them to the user. The system integrates two known presentations of the retrieved results, the ranked list and clustering visualization, in a novel and effective way. It accepts the user's input and adjusts the document visualization accordingly. We give a brief overview of the system document clustering overview InfoVis 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Leuski, A. Allan, J. infovis00--857699 10/09/2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Using Visualization to Detect Plagiarism in Computer Science Classes. This paper introduces a number of general methods for visualizing commonality in sets of text files. Each visualization simultaneously compares one file in the set to all other files in the set. These visualizations, which can be computed in O(n) time and space, are explained and then applied to the problem of detecting plagiarism in large computer science classes. A case study is presented and sample visualizations are provided. Finally, a new interactive tool that can be used to produce and manipulate these visualizations is presented. InfoVis 2000 Information Visualization, 2000. InfoVis 2000. IEEE Symposium on Ribler, R. Abrams, M. text case study infovis01--963273 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Visualizing time-series on spirals. In this paper, we present a new approach for the visualization of time-series data based on spirals. Different to classical bar charts and line graphs, the spiral is suited to visualize large data sets and supports much better the identification of periodic structures in the data. Moreover, it supports both the visualization of nominal and quantitative data based on a similar visualization metaphor. The extension of the spiral visualization to 3D gives access to concepts for zooming and focusing and linking in the data set. As such, spirals complement other visualization techniques for time series and specifically enhance the identication of periodic patterns. zooming information visualization time series InfoVis graph drawing nominal 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Weber, M. Alexa, M. Muller, W. visualization of time-series data data mining infovis01--963274 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Change blindness in information visualization: a case study. Change blindness occurs when people do not notice changes in visible elements of a scene. If people use an information visualization system to compare document collection subsets partitioned by their time-stamps, change blindness makes it impossible for them to recognize even very major changes, let alone minor ones. We describe theories from cognitive science that account for the change blindness phenomenon, as well as solutions developed for two visual analysis tools, a dot plot ( SPIRE Galaxies) and landscape (ThemeView¢â) visualizations. document case study InfoVis Hetzler, E. Nowell, L. 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Tanasse, T. infovis01--963275 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Cluster stability and the use of noise in interpretation of clustering. A clustering and ordination algorithm suitable for mining extremely large databases, including those produced by microarray expression studies, is described and analyzed for stability. Data from a yeast cell cycle experiment with 6000 genes and 18 experimental measurements per gene are used to test this algorithm under practical conditions. The process of assigning database objects to an X,Y coordinate, ordination, is shown to be stable with respect to random starting conditions, and with respect to minor perturbations in the starting similarity estimates. Careful analysis of the way clusters typically co-locate, versus the occasional large displacements under different starting conditions are shown to be useful in interpreting the data. This extra stability information is lost when only a single cluster is reported, which is currently the accepted practice. However, it is believed that the approaches presented here should become a standard part of best practices in analyzing computer clustering of large data collections. cluster clustering experiment database InfoVis 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Davidson, G.S. Wylie, B.N. Boyack, K.W. infovis01--963277 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Technical note: visually encoding program test information to find faults in software. Large test suites are frequently used to evaluate software systems and to locate errors. Unfortunately, this process can generate a huge amount of data that is difficult to interpret manually. We have created a system, TARANTULA, that visually encodes test data to help find program errors. The system uses a principled color mapping to represent how source lines act in passed and failed tests. It also provides a flexible user interface for examining different perspectives that show the behavior of the source code on test sets, ranging from individual tests, to important subsets such as the set of failed tests, to the entire test suite. Stasko, J. InfoVis color Eagan, J. 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Harrold, M.J. Jones, J.A. infovis01--963278 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Getting along: composition of visualization paradigms. This paper describes how focus+context techniques can be composed with other high-level visualization paradigms to mutual advantage. Examples are given showing composition both with a pan&zoom system, and with a treemap implementation. The examples illustrate how focus+context can be used as an exploration and navigation tool within those paradigms. navigation zoom InfoVis treemap focus+context Keahey, T.A. 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on infovis01--963279 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Animated exploration of dynamic graphs with radial layout. We describe a new animation technique for supporting interactive exploration of a graph. We use the wellknown radial tree layout method, in which the view is determined by the selection of a focus node. Our main contribution is a method for animating the transition to a new layout when a new focus node is selected. In order to keep the transition easy to follow, the animation linearly interpolates the polar coordinates of the nodes, while enforcing ordering and orientation constraints. We apply this technique to visualizations of social networks and of the Gnutella file-sharing network, and discuss the results from our informal usability tests. Fisher, D. social network graph usability interaction radial animation animation InfoVis graph drawing 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Yee, K.-P. Dhamija, R. Hearst, M. infovis01--963280 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Effective graph visualization via node grouping. We discuss four methodologies for the application of node grouping in graph visualization. In addition, we introduce techniques for force-directed and orthogonal drawing which use node grouping information and have been shown in experiments to perform better than previous techniques. Not only do these techniques have significantly improved performance with respect to standard aesthetic measures, but they also attain qualitative improvement. graph InfoVis graph visualization graph drawing 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Six, J.M. Tollis, I.G. force-directed drawing orthogonal drawing node grouping experimental studies infovis01--963281 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Visualization of state transition graphs. A new method for the visualization of state transition graphs is presented. Visual information is reduced by clustering nodes, forming a tree structure of related clusters. This structure is visualized in three dimensions with concepts from cone trees and emphasis on symmetry. The resulting visualization makes it easier to relate features in the visualization of the state transition graph to semantic concepts in the corresponding process and vice versa. graph clustering InfoVis van Ham, F. van Wijk, J.J. 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on van de Wetering, H. infovis01--963282 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Graph sketches. We introduce the notion of Graph Sketches. They can be thought of as visual indices that guide the navigation of a multi-graph too large to fit on the available display. We adhere to the Visual Information-Seeking Mantra: Overview first, zoom and filter, then details on demand. Graph Sketches are incorporated into MGV, an integrated visualization and exploration system for massive multi-digraph navigation. We highlight the main algorithmic and visualization tasks behind the computation of Graph Sketches and illustrate several application scenarios. Graph Sketches will be used to guide the navigation of multi-digraphs defined on vertex sets with sizes ranging from 100 to 250 million vertices. visualization graph overview filter navigation zoom InfoVis hierarchies Abello, J. graphs 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Korn, J. massive data sets Finocchi, I. infovis01--963283 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Ordered treemap layouts. Treemaps, a space-filling method of visualizing large hierarchical data sets, are receiving increasing attention. Several algorithms have been proposed to create more useful displays by controlling the aspect ratios of the rectangles that make up a treemap. While these algorithms do improve visibility of small items in a single layout, they introduce instability over time in the display of dynamically changing data, and fail to preserve an ordering of the underlying data. This paper introduces the ordered treemap, which addresses these two shortcomings. The ordered treemap algorithm ensures that items near each other in the given order will be near each other in the treemap layout. Using experimental evidence from Monte Carlo trials, we show that compared to other layout algorithms ordered treemaps are more stable while maintaining relatively favorable aspect ratios of the constituent rectangles. A second test set uses stock market data. Shneiderman, B. Wattenberg, M. information visualization InfoVis treemap hierarchies treemap trees 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on ordered treemaps infovis01--963284 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Collapsible cylindrical trees: a fast hierarchical navigation technique. This paper proposes a new visualization and interaction technique for medium-sized trees, called Collapsible Cylindrical Trees (CCT). Child nodes are mapped on rotating cylinders, which will be dynamically displayed or hidden to achieve a useful balance of detail and context. Besides a comprehensible threedimensional visualization of trees, the main feature of CCT is a very fast and intuitive interaction with the displayed nodes. Only a single click is needed to reach every node and perform an action on it, such as displaying a web page. The CCT browsing technique was developed for interaction with web hierarchies but is not limited to this domain. We also present sample implementations of CCT using VRML, which show the usefulness of this intuitive tree navigation technique. interaction visualization navigation hierarchies InfoVis 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on hierarchy Dachselt, R. Ebert, J. web navigation interactive tree sitemap 3D graphics VRML XML infovis01--963285 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Botanical visualization of huge hierarchies. A new method for the visualization of huge hierarchical data structures is presented. The method is based on the observation that we can easily see the branches, leaves, and their arrangement in a botanical tree, despite of the large number of elements. The strand model of Holton is used to convert an abstract tree into a geometric model. Nonleaf nodes are mapped to branches and child nodes to subbranches. A naive application of this model leads to unsatisfactory results, hence it is tailored to suit our purposes better. Continuing branches are emphasized, long branches are contracted, and sets of leaves are shown as fruit. The method is applied to the visualization of directory structures. The elements, directories and files, as well as their relations can easily be extracted, thereby showing that the use of methods from botanical modeling can be effective for information visualization. hierarchies tree visualization InfoVis van Wijk, J.J. 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on van de Wetering, H. Kleiberg, E. botanical tree logical tree huge hierarchy strands directory tree phyllotaxis infovis01--963286 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Semantic depth of field. We present a new technique called Semantic Depth of Field (SDOF) as an alternative approach to focus-andcontext displays of information. We utilize a well-known method from photography and cinematography (depth-offield effect) for information visualization, which is to blur different parts of the depicted scene in dependence of their relevance. Independent of their spatial locations, objects of interest are depicted sharply in SDOF, whereas the context of the visualization is blurred. In this paper, we present a flexible model of SDOF which can be easily adopted to various types of applications. We discuss pros and cons of the new technique, give examples of application, and describe a fast prototype implementation of SDOF. information visualization Kosara, R. InfoVis Hauser, H. 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Miksch, S. depth of field focus+context infovis01--963287 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Interactive visualization of multiple query results. This paper introduces a graphical method for visually presenting and exploring the results of multiple queries simultaneously. This method allows a user to visually compare multiple query result sets, explore various combinations among the query result sets, and identify the ¡°best¡± matches for combinations of multiple independent queries. This approach might also help users explore methods for progressively improving queries by visually comparing the improvement in result sets. InfoVis Hetzler, E. Perrine, K. 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Jurrus, E. Havre, S. Miller, N. infovis01--963288 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Pixel bar charts: a new technique for visualizing large multi-attribute data sets without aggregation. Simple presentation graphics are intuitive and easy-to-use, but show only highly aggregated data and present only a very limited number of data values (as in the case of bar charts). In addition, these graphics may have a high degree of overlap which may occlude a significant portion of the data values (as in the case of the x-y plots). In this paper, we therefore propose a generalization of traditional bar charts and x-y-plots which allows the visualization of large amounts of data. The basic idea is to use the pixels within the bars to present the detailed information of the data records. Our so-called pixel bar charts retain the intuitiveness of traditional bar charts while allowing very large data sets to be visualized in an effective way. We show that, for an effective pixel placement, we have to solve complex optimization problems, and present an algorithm which efficiently solves the problem. Our application using real-world e-commerce data shows the wide applicability and usefulness of our new idea. Keim, D.A. pixel Hao, M.C. Dayal, U. InfoVis 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Hsu, M. Ladisch, J. infovis01--963289 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on An empirical comparison of three commercial information visualization systems. An empirical comparison of three commercial information visualization systems on three different databases is presented. The systems use different paradigms for visualizing data. Tasks were selected to be "ecologically relevant", i.e. meaningful and interesting in the respective domains. Users of one system turned out to solve problems significantly faster than users of the other two, while users of another system would supply significantly more correct answers. Reasons for these results and general observations about the studied systems are discussed. InfoVis Kobsa, A. 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on infovis01--963290 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on A comparison of 2-D visualizations of hierarchies. This paper describes two experiments that compare four two-dimensional visualizations of hierarchies: organization chart, icicle plot, treemap, and tree ring. The visualizations are evaluated in the context of decision tree analyses prevalent in data mining applications. The results suggest that either the tree ring or icicle plot is equivalent to the organization chart. data mining hierarchies InfoVis treemap 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Barlow, T. Neville, P. infovis01--963291 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on 2D vs 3D, implications on spatial memory. Since the introduction of graphical user interfaces (GUI) and two-dimensional (2D ) displays, the concept of space has entered the information technology (IT) domain. Interactions with computers were re-encoded in terms of fidelity to the interactions with real environment and consequently in terms of fitness to cognitive and spatial abilities. A further step in this direction was the creation of three-dimensional (3D) displays which have amplified the fidelity of digital representations. However, there are no systematic results evaluating the extent to which 3D displays better support cognitive spatial abilities. The aim of this research is to empirically investigate spatial memory performance across different instances of 2D and 3D displays. Two experiments were performed. The displays used in the experimental situation represented hierarchical information structures. The results of the test show that the 3D display does improve performances in the designed spatial memory task. InfoVis Lind, M. 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Tavanti, M. infovis01--963292 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Case study: visualization for decision tree analysis in data mining. Decision trees are one of the most popular methods of data mining. Decision trees partition large amounts of data into smaller segments by applying a series of rules. Creating and evaluating decision trees benefits greatly from visualization of the trees and diagnostic measures of their effectiveness. This paper describes an application, EMTree Results Viewer, that supports decision tree analysis through the visualization of model results and diagnosis. The functionality of the application and the visualization techniques are revealed through an example of churn analysis in the telecommunications industry. case study data mining InfoVis 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Barlow, T. Neville, P. infovis01--963293 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Case study: e-commerce clickstream visualization. We have developed an interactive, scalable visualization tool for analyzing the behavior of users of a web site. Our system not only shows site topology and traffic flow, but by segmenting site traffic data based on user attributes, including demographic data and purchase history, we can present a more complete picture of web site usage. This can lead to a more focussed analysis that allows direct comparison between user segments, and ultimately a deeper understanding of how users interact with a site. The tool is designed for real world use, and we present a usage study of the tool by analyzing the data of a failed ¡°dot-com¡±. case study history InfoVis 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Becker, B.G. Brainerd, J. infovis01--963294 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Case study: design and assessment of an enhanced geographic information system for exploration of multivariate health statistics. An implementation of an interactive parallel coordinate plot linked with the ArcView¢ç geographic information system (GIS) is presented. The integrated geographic visualization system was created for the exploratory analysis of mortality data from specific cancers as they relate, specifically spatially, to other mortality causes and to demographic and socioeconomic risk factors. The linked and interactive parallel coordinate plot was tested with and compared to a similarly interactive and linked scatterplot in usability assessments designed to assess each representation¡¯s relative effectiveness for exploration of these data sets. Evidence from these studies suggests that multivariate, spatial, and/or time series exploration is enhanced through the use of the parallel coordinate plot linked to maps geographic case study usability time series scatterplot statistics MacEachren, A.M. InfoVis 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Pickle, L. Edsall, R.M. infovis01--963295 10/22/2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Graphic data display for cardiovascular system. Our multi-disciplinary group has developed a visual representation for cardiovascular physiological variables. This enhances a clinician¡¯s ability to detect and rapidly respond to critical events. The integrated and intuitive display communicates a patient¡¯s cardiovascular state so that it is easily and quickly understood without prior training. The display is designed to show patterns of functional relationships that aid in the detection, diagnosis, and treatment of a critical event. InfoVis Agutter, J. 2001 Information Visualization, 2001. INFOVIS 2001. IEEE Symposium on Syroid, N. Drews, F. Westenskow, D. Bermudez, J. Strayer, D. infovis02--1173141 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Multiscale visualization using data cubes. Most analysts start with an overview of the data before gradually refining their view to be more focused and detailed. Multiscale pan-and-zoom systems are effective because they directly support this approach. However generating abstract overviews of large data sets is difficult, and most systems take advantage of only one type of abstraction: visual abstraction. Furthermore, these existing systems limit the analyst to a single zooming path on their data and thus a single set of abstract views. This paper presents: (1) a formalism for describing multiscale visualizations of data cubes with both data and visual abstraction, and (2) a method for independently zooming along one or more dimensions by traversing a zoom graph with nodes at different levels of detail. As an example of how to design multiscale visualizations using our system, we describe four design patterns using our formalism. These design patterns show the effectiveness of multiscale visualization of general relational databases. zooming graph overview Hanrahan, P. Tang, D. zoom InfoVis Stolte, C. 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on infovis02--1173142 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Visualization schemas for flexible information visualization. Relational databases provide significant flexibility to organize, store, and manipulate an infinite variety of complex data collections. This flexibility is enabled by the concept of relational data schemas, which allow data owners to easily design custom databases according to their unique needs. However, user interfaces and information visualizations for accessing and utilizing databases have not kept pace with this level of flexibility. This paper introduces the concept of visualization schemas, based on the Snap-Together Visualization model, which are analogous to relational data schemas. Visualization schemas enable users to rapidly construct customized multiple-view visualizations for databases in a similarly flexible fashion without programming. Since the design of appropriate visualizations for a given database depends on the data schema, visualization schemas are a natural analogy to the data schema concept. North, C. database InfoVis 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Conklin, N. Saini, V. infovis02--1173143 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Building a visual database for example-based graphics generation. Example-based graphics generation systems automatically create new information visualizations by learning from existing graphic examples. As part of the effort on developing a general-purpose example-based generation system, we are building a visual database of graphic examples. In this paper, we address two main issues involved in constructing such a database: example selection and example modeling. As a result, our work offers three unique contributions: First, we build a visual database that contains a diverse collection of well-designed examples. Second, we develop a feature-based scheme to model all examples uniformly and accurately. Third, our visual database brings several important implications to the area of information visualization. Zhou, M.X. database InfoVis Chen, M. 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Feng, F. infovis02--1173144 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Efficient cartogram generation: a comparison. Cartograms are a well-known technique for showing geography-related statistical information, such as population demographics and epidemiological data. The basic idea is to distort a map by resizing its regions according to a statistical parameter, but in a way that keeps the map recognizable. We deal with the problem of making continuous cartograms that strictly retain the topology of the input mesh. We compare two algorithms to solve the continuous cartogram problem. The first one uses an iterative relocation of the vertices based on scanlines. The second one is based on the Gridfit technique, which uses pixel-based distortion based on a quadtree-like data structure. Keim, D.A. pixel Schneidewind, J. distortion InfoVis North, S. Panse, C. 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on infovis02--1173145 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Visualizing data with bounded uncertainty. Visualization is a powerful way to facilitate data analysis, but it is crucial that visualization systems explicitly convey the presence, nature, and degree of uncertainty to users. Otherwise, there is a danger that data will be falsely interpreted, potentially leading to inaccurate conclusions. A common method for denoting uncertainty is to use error bars or similar techniques designed to convey the degree of statistical uncertainty. While uncertainty can often be modeled statistically, a second form of uncertainty, bounded uncertainty, can also arise that has very different properties than statistical uncertainty. Error bars should not be used for bounded uncertainty because they do not convey the correct properties, so a different technique should be used instead. We describe a technique for conveying bounded uncertainty in visualizations and show how it can be applied systematically to common displays of abstract charts and graphs. Interestingly, it is not always possible to show the exact degree of uncertainty, and in some cases it can only be displayed approximately. uncertainty InfoVis uncertainty visualization Mackinlay, J.D. 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Olston, C. bounded uncertainty infovis02--1173146 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Graphical encoding for information visualization: an empirical study. Research in several areas provides scientific guidance for use of graphical encoding to convey information in an information visualization display. By graphical encoding we mean the use of visual display elements such as icon color, shape, size, or position to convey information about objects represented by the icons. Literature offers inconclusive and often conflicting viewpoints, including the suggestion that the effectiveness of a graphical encoding depends on the type of data represented. Our empirical study suggests that the nature of the users' perceptual task is more indicative of the effectiveness of a graphical encoding than the type of data represented. InfoVis color 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Nowell, L. Schulman, R. Hix, D. infovis02--1173147 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on The illusion of perceived metric 3D structure. A large body of results on the characteristics of human spatial vision suggests that space perception is distorted. Recent studies indicate that the geometry of visual space is best understood as Affine. If this is the case, it has far reaching implications on how 3D visualizations can be successfully employed. For instance, all attempts to build visualization systems where users are expected to discover relations based on Euclidean distances or shapes will be ineffective. Because visualization can, and sometimes do, employ all possible types of depth information and because the results from vision research usually concentrates on one or two such types, three experiments were performed under near optimal viewing conditions. The aim of the experiments was twofold: To test whether the earlier findings generalize to optimal viewing conditions and to get a sense of the size of the error under such conditions. The results show that the findings do generalize and that the errors are large. The implications of these results for successful visualizations are discussed. perception InfoVis Lind, M. 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Bingham, G.P. Forser, C. infovis02--1173148 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on SpaceTree: supporting exploration in large node link tree, design evolution and empirical evaluation. We present a novel tree browser that builds on the conventional node link tree diagrams. It adds dynamic rescaling of branches of the tree to best fit the available screen space, optimized camera movement, and the use of preview icons summarizing the topology of the branches that cannot be expanded. In addition, it includes integrated search and filter functions. This paper reflects on the evolution of the design and highlights the principles that emerged from it. A controlled experiment showed benefits for navigation to already previously visited nodes and estimation of overall tree topology. evaluation filter Plaisant, C. navigation experiment Bederson, B.B. InfoVis 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Grosjean, J. infovis02--1173149 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Process visualization with levels of detail. We demonstrate how we apply information visualization techniques to process monitoring. Virtual instruments are enhanced using history encoding instruments are capable of displaying the current value and the value from the near past. Multi-instruments are capable of displaying several data sources simultaneously. Levels of detail for virtual instruments are introduced where the screen area is inversely proportional to the information amount displayed. Furthermore the monitoring system is enhanced by using: 3D anchoring attachment of instruments to positions on a 3D model, collision avoidance a physically based spring model prevents instruments from overlapping, and focus+context rendering - giving the user a possibility to examine particular instruments in detail without loosing the context information. history information visualization InfoVis focus+context Hauser, H. Matkovic, K. Groller, M.E. process visualization 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on focus+context visualization Sainitzer, R. levels of detail infovis02--1173150 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Case study: visualizing sets of evolutionary trees. We describe a visualization tool which allows a biologist to explore a large set of hypothetical evolutionary trees. Interacting with such a dataset allows the biologist to identify distinct hypotheses about how different species or organisms evolved, which would not have been clear from traditional analyses. Our system integrates a point-set visualization of the distribution of hypothetical trees with detail views of an individual tree, or of a consensus tree summarizing a subset of trees. Efficient algorithms were required for the key tasks of computing distances between trees, finding consensus trees, and laying out the point-set visualization. case study InfoVis Klingner, J. 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Amenta, N. infovis02--1173151 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on InterRing: an interactive tool for visually navigating and manipulating hierarchical structures. Radial, space-filling (RSF) techniques for hierarchy visualization have several advantages over traditional node-link diagrams, including the ability to efficiently use the display space while effectively conveying the hierarchy structure. Several RSF systems and tools have been developed to date, each with varying degrees of support for interactive operations such as selection and navigation. We describe what we believe to be a complete set of desirable operations on hierarchical structures. We then present InterRing, an RSF hierarchy visualization system that supports a significantly more extensive set of these operations than prior systems. In particular, InterRing supports multi-focus distortions, interactive hierarchy reconfiguration, and both semi-automated and manual selection. We show the power and utility of these and other operations, and describe our on-going efforts to evaluate their effectiveness and usability. Yang, J. usability Ward, M.O. Rundensteiner, E.A. navigation radial hierarchy InfoVis 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on radial space-filling hierarchy visualization multifocus distortion structure-based brushing infovis02--1173152 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on A space-optimized tree visualization. We describe a new method for the visualization of tree structured relational data. It can be used especially for the display of very large hierarchies in a 2-dimensional space. We discuss the advantages and limitations of current techniques of tree visualization. Our strategy is to optimize the drawing of trees in a geometrical plane and maximize the utilization of display space by allowing more nodes and links to be displayed at a limit screen resolution. We use the concept of enclosure to partition the entire display space into a collection of local regions that are assigned to all nodes in tree T for the display of their sub-trees and themselves. To enable the exploration of large hierarchies, we use a modified semantic zooming technique to view the detail of a particular part of the hierarchy at a time based on user's interest. Layout animation is also provided to preserve the mental map while the user is exploring the hierarchy by changing zoomed views. zooming animation hierarchy hierarchies InfoVis 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Nguyen, Q.V. Huang, M.L. infovis02--1173153 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Beamtrees: compact visualization of large hierarchies. Beamtrees are a new method for the visualization of large hierarchical data sets. Nodes are shown as stacked circular beams, such that both the hierarchical structure as well as the size of nodes are depicted. The dimensions of beams are calculated using a variation of the treemap algorithm. A small user study indicated that beamtrees are significantly more effective than nested treemaps and cushion treemaps for the extraction of global hierarchical information. user study hierarchies InfoVis treemap van Ham, F. van Wijk, J.J. 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on infovis02--1173154 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Visualizing biosequence data using texture mapping. Data-mining of information by the process of pattern discovery in protein sequences has been predominantly algorithm based. We discuss a visualization approach, which uses texture mapping and blending techniques to perform visual data-mining on text data obtained from discovering patterns in protein sequences. This visual approach, investigates the possibilities of representing text data in three dimensions and provides new possibilities of representing more dimensions of information in text data visualization and analysis. We also present a generic framework derived from this visualization approach to visualize text in biosequence data. text InfoVis 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Thiagarajan, P.R. Gao, G.R. infovis02--1173155 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Arc diagrams: visualizing structure in strings. This paper introduces a new visualization method, the arc diagram, which is capable of representing complex patterns of repetition in string data. Arc diagrams improve over previous methods such as dotplots because they scale efficiently for strings that contain many instances of the same subsequence. This paper describes design and implementation issues related to arc diagrams and shows how they may be applied to visualize such diverse data as music, text, and compiled code. visualization text Wattenberg, M. InfoVis music text 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on string sequence arc diagram code infovis02--1173156 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Interactive information visualization of a million items. Existing information visualization techniques are usually limited to the display of a few thousand items. This article describes new interactive techniques capable of handling a million items (effectively visible and manageable on screen). We evaluate the use of hardware-based techniques available with newer graphics cards, as well as new animation techniques and non-standard graphical features such as stereovision and overlap count. These techniques have been applied to two popular information visualizations: treemaps and scatter plot diagrams; but are generic enough to be applied to other 2D representations as well. Fekete, J.-D. Plaisant, C. hardware animation InfoVis 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on infovis02--1173157 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Angular brushing of extended parallel coordinates. In this paper we present angular brushing for parallel coordinates (PC) as a new approach to highlighting rational data-properties, i.e., features which - in a non-separable way - depend on two data dimensions. We also demonstrate smooth brushing as an intuitive tool for specifying nonbinary degree-of-interest functions (for focus+context visualization). We also briefly describe our implementation as well as its application to the visualization of CFD data. parallel coordinates information visualization brushing parallel coordinates InfoVis brushing focus+context Hauser, H. 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on focus+context visualization Ledermann, F. Doleisch, H. linear correlations infovis02--1173158 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Multiple foci drill-down through tuple and attribute aggregation polyarchies in tabular data. Information analysis often involves decomposing data into sub-groups to allow for comparison and identification of relationships. Breakdown Visualization provides a mechanism to support this analysis through user guided drill-down of polyarchical metadata. This metadata describes multiple hierarchical structures for organizing tuple aggregations and table attributes. This structure is seen in financial data, organizational structures, sport statistics, and other domains. A spreadsheet format enables comparison of visualizations at any level of the hierarchy. Breakdown Visualization allows users to drill-down a single hierarchy then pivot into another hierarchy within the same view. It utilizes a fix and move technique that allows users to select multiple foci for drill-down. North, C. financial statistics hierarchy InfoVis 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Conklin, N. Prabhakar, S. infovis02--1173159 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on ACE: a fast multiscale eigenvectors computation for drawing huge graphs. We present an extremely fast graph drawing algorithm for very large graphs, which we term ACE (for Algebraic multigrid Computation of Eigenvectors). ACE exhibits an improvement of something like two orders of magnitude over the fastest algorithms we are aware of; it draws graphs of millions of nodes in less than a minute. ACE finds an optimal drawing by minimizing a quadratic energy function. The minimization problem is expressed as a generalized eigenvalue problem, which is rapidly solved using a novel algebraic multigrid technique. The same generalized eigenvalue problem seems to come up also in other fields, hence ACE appears to be applicable outside of graph drawing too. graph InfoVis Koren, Y. graph drawing graph drawing 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Carmel, L. Harel, D. algebraic multigrid multiscale/multilevel optimization generalized eigenvalue problem Fiedler vector force-directed layout the Hall energy infovis02--1173160 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Visual unrolling of network evolution and the analysis of dynamic discourse. A new method for visualizing the class of incrementally evolving networks is presented. In addition to the intermediate states of the network it conveys the nature of the change between them by unrolling the dynamics of the network. Each modification is shown in a separate layer of a three-dimensional representation, where the stack of layers corresponds to a time line of the evolution. We focus on discourse networks as the driving application, but our method extends to any type of network evolving in similar ways. network Brandes, U. InfoVis 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Corman, S.R. infovis02--1173161 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on A hybrid layout algorithm for sub-quadratic multidimensional scaling. Many clustering and layout techniques have been used for structuring and visualising complex data. This paper is inspired by a number of such contemporary techniques and presents a novel hybrid approach based upon stochastic sampling, interpolation and spring models. We use Chalmers' 1996 O(N2) spring model as a benchmark when evaluating our technique, comparing layout quality and run times using data sets of synthetic and real data. Our algorithm runs in O(N¡îN) and executes significantly faster than Chalmers' 1996 algorithm, whilst producing superior layouts. In reducing complexity and run time, we allow the visualisation of data sets of previously infeasible size. Our results indicate that our method is a solid foundation for interactive and visual exploration of data. clustering InfoVis Chalmers, M. Ross, G. 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Morrison, A. infovis02--1173162 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Demystifying venture capital investing. Since the crash of the dot.coms, investors have gotten a lot more careful with where they place their money. Now more than ever it becomes really important for venture capitalists (VCs) to monitor the state of the startups market and continually update their investment strategy to suit the rapidly changing market conditions. This paper presents three new visualization metaphors (Spiral Map, TimeTicker, and Double Histogram) for monitoring the startups market. While we are focusing on the VC domain, the visual metaphors developed are general and can be easily applied to other domains. InfoVis 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Chuah, M.C. infovis02--1173163 10/28/2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on Visual path analysis. We describe a system for analyzing the flow of traffic through Web sites. We decomposed the general path analysis problem into a set of distinct subproblems, and created a visual metaphor for analyzing each of them. Our system works off of multiple representations of the clickstream, and exposes the path extraction algorithms and data to the visual metaphors as Web services. We have combined the visual metaphors into a Web-based "path analysis portal" that lets the user easily switch between the different modes of analysis. Eick, S.G. InfoVis Keahey, T.A. 2002 Information Visualization, 2002. INFOVIS 2002. IEEE Symposium on infovis03--1295823 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Developing architectural lighting representations. This paper reports on the development of a visualization system for architectural lighting designers. It starts by motivating the problem as both complex in its physics and social organization. Three iterations of prototypes for displaying time and space varying phenomena are discussed. Fieldwork is presented to identify where in practice they will be most effective. A set of user studies, one of which is analyzed in fine-grained detail, show how building designers incorporate visualization on hypothetical design problems. This has positive implications for both energy efficiency and lighting quality in buildings. social information visualization information visualization InfoVis Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 Glaser, D.C. Tan, R. Canny, J. Do, E.Y. qualitative analysis ethnographics fieldwork architectural lighting design energy efficiency infovis03--1284026 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on BARD: a visualization tool for biological sequence analysis. We present BARD (biological arc diagrams), a visualization tool for biological sequence analysis. The development of BARD began with the application of Wattenberg's arc diagrams [Wattenberg 2002] to results from sequence analysis programs, such as BLAST [Altschul et al. 1990]. In this paper, we extend the initial arc diagram concept in two ways: 1) by separating the visualization method from the underlying matching algorithm and 2) by expanding the types of matches to include inexact matches, complemented palindrome matches, and inter-sequence matches. BARD renders each type of match distinctly, resulting in a powerful tool to quickly understand sequence similarities and differences. We illustrate the power of BARD by applying the technique to a comparative sequence analysis of the human pathogenic fungi Cryptococcus neoformans. visualization information visualization InfoVis Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 Spell, R. Brady, R. Dierich, F. sequence analysis comparative genomics ard diagram BARD infovis03--1249031 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Between aesthetics and utility: designing ambient information visualizations. Unlike traditional information visualization, ambient information visualizations reside in the environment of the user rather than on the screen of a desktop computer. Currently, most dynamic information that is displayed in public places consists of text and numbers. We argue that information visualization can be employed to make such dynamic data more useful and appealing. However, visualizations intended for non-desktop spaces will have to both provide valuable information and present an attractive addition to the environment - they must strike a balance between aesthetical appeal and usefulness. To explore this, we designed a real-time visualization of bus departure times and deployed it in a public space, with about 300 potential users. To make the presentation more visually appealing, we took inspiration from a modern abstract artist. The visualization was designed in two passes. First, we did a preliminary version that was presented to and discussed with prospective users. Based on their input, we did a final design. We discuss the lessons learned in designing this and previous ambient information visualizations, including how visual art can be used as a design constraint, and how the choice of information and the placement of the display affect the visualization. text data visualisation information visualization InfoVis aesthetics Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 computer displays aesthetics Holmquist, L.E. Skog, T. Ljungblad, S. art information use large screen displays multimedia systems vehicles bus departure times design constraint dynamic information modern abstract artist nondesktop spaces real-time visualization ambient information visualizations valuable information visual art ambient displays ambient information visualization calm technology informative art infovis03--1249028 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Thread Arcs: an email thread visualization. This paper describes Thread Arcs, a novel interactive visualization technique designed to help people use threads found in email. Thread Arcs combine the chronology of messages with the branching tree structure of a conversational thread in a mixed-model visualization by Venolia and Neustaedter (2003) that is stable and compact. By quickly scanning and interacting with Thread Arcs, people can see various attributes of conversations and find relevant messages in them easily. We tested this technique against other visualization techniques with users' own email in a functional prototype email client. Thread Arcs proved an excellent match for the types of threads found in users' email for the qualities users wanted in small-scale visualizations. data visualisation graphical user interfaces interactive visualization information visualization information visualization user interface InfoVis Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 tree data structures Kerr, B. electronic mail Thread Arcs branching tree structure conversational thread email client email thread visualization message chronology mixed-model visualization conversations discussions electronic mail email threads tree structures infovis03--1249027 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on FundExplorer: supporting the diversification of mutual fund portfolios using context treemaps. An equity mutual fund is a financial instrument that invests in a set of stocks. Any two different funds may partially invest in some of the same stocks, thus overlap is common. Portfolio diversification aims at spreading an investment over many different stocks in search of greater returns. Helping people with portfolio diversification is challenging because it requires informing them about both their current portfolio of stocks held through funds and the other stocks in the market not invested in yet. Current stock/fund visualization systems either waste screen real estate and visualization of all data points. We have developed a system called FundExplorer that implements a distorted treemap to visualize both the amount of money invested in a person's fund portfolio and the context of remaining market stocks. The FundExplorer system enables people to interactively explore diversification possibilities with their portfolios. context financial data visualisation Stasko, J. information visualization InfoVis treemap treemap distortion Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 tree data structures financial data processing Csallner, C. Handte, M. Lehmann, O. investment stock markets context treemaps distorted treemap diversification support equity mutual fund financial instrument fund visualization systems investment visualization mutual fund portfolios portfolio diversification stock market stock visualization systems stocks investment query financial data stock market FundExplorer infovis03--1249026 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Visualization of large-scale customer satisfaction surveys using a parallel coordinate tree. Satisfaction surveys are an important measurement tool in fields such as market research or human resources management. Serious studies consist of numerous questions and contain answers from large population samples. Aggregation on both sides, the questions asked as well as the answers received, turns the multidimensional problem into a complex system of interleaved hierarchies. Traditional ways of presenting the results are limited to one-dimensional charts and cross-tables. We developed a visualization method called the Parallel Coordinate Tree that combines multidimensional analysis with a tree structure representation. Distortion-oriented focus+context techniques are used to facilitate interaction with the visualization. In this paper we present a design study of a commercial application that we built, using this method to analyze and communicate results from large-scale customer satisfaction surveys. interaction data visualisation graphical user interfaces customer satisfaction parallel coordinates hierarchies distortion InfoVis design study focus+context focus+context hierarchical data Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 human factors tree data structures Brodbeck, D. Girardin, L. marketing data processing multidimensional systems parallel programming customer satisfaction surveys distortion-oriented focus+context techniques human resources management market research measurement tool multidimensional analysis parallel coordinate tree tree structure representation satisfaction survey infovis03--1249025 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Causality visualization using animated growing polygons. We present Growing Polygons, a novel visualization technique for the graphical representation of causal relations and information flow in a system of interacting processes. Using this method, individual processes are displayed as partitioned polygons with color-coded segments showing dependencies to other processes. The entire visualization is also animated to communicate the dynamic execution of the system to the user. The results from a comparative user study of the method show that the Growing Polygons technique is significantly more efficient than the traditional Hasse diagram visualization for analysis tasks related to deducing information flow in a system for both small and large executions. Furthermore, our findings indicate that the correctness when solving causality tasks is significantly improved using our method. In addition, the subjective ratings of the users rank the method as superior in all regards, including usability, efficiency, and enjoyability. user study usability data visualisation interactive systems graphical user interfaces information visualization information visualization Elmqvist, N. Tsigas, P. InfoVis color Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 computer animation software engineering concurrent engineering Hasse diagram visualization animated growing polygons causal relations causality visualization color coded segments dynamic execution graphical representation information flow interactive animation partitioned polygons subjective user ratings causal relations interactive animation infovis03--1249023 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Coordinated graph and scatter-plot views for the visual exploration of microarray time-series data. Microarrays are relatively new, high-throughput data acquisition technology for investigating biological phenomena at the micro-level. One of the more common procedures for microarray experimentation is that of the microarray time-course experiment. The product of microarray time-course experiment is time-series data, which subject to proper analysis has the potential to have significant impact on the diagnosis, treatment, and prevention of diseases. While existing information visualization techniques go some way to making microarray time-series data more manageable, requirements analysis has revealed significant limitations. The main finding was that users were unable to uncover and quantify common changes in value over a specified time-period. This paper describes a novel technique that provides this functionality by allowing the user to visually formulate and modify measurable queries with separate time-period and condition components. These visual queries are supported by the combination of a traditional value against time graph representation of the data with a complementary scatter-plot representation of a specified time-period. The multiple views of the visualization are coordinated so that the user can formulate and modify queries with rapid reversible display of query results in the traditional value against time graph format. information visualization graph data visualisation multiple views visual exploration user interfaces bioinformatics experiment bioinformatics InfoVis time series Kennedy, J. Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 query formulation Craig, P. data acquisition biological phenomena investigation disease diagnosis disease prevention disease treatment graph view information visualization techniques microarray experimentation microarray time-course experiment microarray time-series data microarrays multiple views requirements analysis scatter-plot view time graph data representation visual queries microarrays time series multiple views infovis03--1249022 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Conveying shape with texture: an experimental investigation of the impact of texture type on shape categorization judgments. As visualization researchers, we are interested in gaining a better understanding of how to effectively use texture to facilitate shape perception. If we could design the ideal texture pattern to apply to an arbitrary smoothly curving shape to be most accurately and effectively perceived, what would the characteristics of that texture pattern be? In this paper we describe the results of a comprehensive controlled observer experiment intended to yield insight into that question. Here, we report the results of a new study comparing the relative accuracy of observers' judgments of shape type (elliptical, cylindrical, hyperbolic or flat) and shape orientation (convex, concave, both, or neither) for local views of boundary masked quadric surface patches under six different principal direction texture pattern conditions plus two texture conditions (an isotropic pattern and a non-principal direction oriented anisotropic pattern), under both perspective and orthographic projection conditions and from both head-on and oblique viewpoints. Our results confirm the hypothesis that accurate shape perception is facilitated to a statistically significantly greater extent by some principal direction texture patterns than by others. Specifically, we found that, for both views, under conditions of perspective projection, participants more often correctly identified the shape category and the shape orientation when the surface was textured with the pattern that contained oriented energy along both the first and second principal directions only than in the case of any other texture condition. Patterns containing markings following only one of the principal directions, or containing information along other directions in addition to the principal directions yielded poorer performance overall. insight data visualisation perception experiment Kim, S. InfoVis Hagh-Shenas, H. Interrante, V. Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 image texturean isotropic pattern arbitrary smoothly curving shape boundary masked quadric surface patches concave controlled observer experiment convex cylindrical shape elliptical shape experimental investigation flat shape head-on viewpoint hyperbolic shape nonprincipal direction oblique viewpoint observer judgments oriented energy orthographic projection conditions perspective projection principal direction texture pattern conditions shape categorization judgments shape category shape conveyance shape orientation shape perception shape type texture type visualization research shape perception texture principal directions infovis03--1249020 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Empirical comparison of dynamic query sliders and brushing histograms. Dynamic queries facilitate rapid exploration of information by real-time visual display of both query formulation and results. Dynamic query sliders are linked to the main visualization to filter data. A common alternative to dynamic queries is to link several simple visualizations, such as histograms, to the main visualization with a brushing interaction strategy. Selecting data in the histograms highlights that data in the main visualization. We compare these two approaches in an empirical experiment on DataMaps, a geographic data visualization tool. Dynamic query sliders resulted in better performance for simple range tasks, while brushing histograms was better for complex trend evaluation and attribute relation tasks. Participants preferred brushing histograms for understanding relationships between attributes and the rich information they provided. interaction geographic evaluation North, C. data visualisation graphical user interfaces filter information visualization information visualization brushing experiment dynamic query InfoVis usability study multidimensional visualization Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 multidimensional visualization dynamic queries query formulation information exploration Li, Q. information filters DataMaps brushing histograms brushing interaction complex trend evaluation dynamic query sliders filter data geographic data visualization real-time visual display dynamic query slider histogram usability study infovis03--1249019 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Constant density displays using diversity sampling. The Informedia Digital Video Library user interface summarizes query results with a collage of representative keyframes. We present a user study in which keyframe occlusion caused difficulties. To use the screen space most efficiently to display images, both occlusion and wasted whitespace should be minimized. Thus optimal choices will tend toward constant density displays. However, previous constant density algorithms are based on global density, which leads to occlusion and empty space if the density is not uniform. We introduce an algorithm that considers the layout of individual objects and avoids occlusion altogether. Efficiency concerns are important for dynamic summaries of the Informedia Digital Video Library, which has hundreds of thousands of shots. Posting multiple queries that take into account parameters of the visualization as well as the original query reduces the amount of work required. This greedy algorithm is then compared to an optimal one. The approach is also applicable to visualizations containing complex graphical objects other than images, such as text, icons, or trees. user study information visualization text data visualisation graphical user interfaces user interface information visualization InfoVis occlusion Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 computer displays hidden feature removal human factors Derthick, M. Christel, M.G. Hauptmann, A.G. Wactlar, H.D. Informedia Digital Video Library constant density algorithms constant density displays diversity sampling global density graphical objects greedy algorithm image display keyframe occlusion query results representative keyframes collage infovis03--1249018 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Intelligently resolving point occlusion. Large and high-dimensional data sets mapped to low-dimensional visualizations often result in perceptual ambiguities. One such ambiguity is overlap or occlusion that occurs when the number of records exceeds the number of unique locations in the presentation or when there exist two or more records that map to the same location. To lessen the affect of occlusion, non-standard visual attributes (i.e. shading and/or transparency) are applied, or such records may be remapped to a corresponding jittered location. The resulting mapping efficiently portrays the crowding of records but fails to provide the insight into the relationship between the neighboring records. We introduce a new interactive technique that intelligibly organizes overlapped points, a neural network-based smart jittering algorithm. We demonstrate this technique on a scatter plot, the most widely used visualization. The algorithm can be applied to other one, two, and multi-dimensional visualizations which represent data as points, including 3-dimensional scatter plots, RadViz, polar coordinates. insight network high-dimensional data data visualisation graphical user interfaces information visualization information visualization design InfoVis data visualization data sets occlusion data visualization occlusion data density Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 multidimensional visualizations transparency neural nets data density data points identifiable points learning (artificial intelligence) hidden feature removal Trutschl, M. Grinstein, G. Cvek, U. jitter RadViz Smart Jittering algorithm low-dimensional visualizations neighboring records neural network neural networks nonstandard visual attributes point occlusion polar coordinates scatter plot shading data points identifiable points jitter neural networks infovis03--1249016 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Mapping nominal values to numbers for effective visualization. Data sets with a large number of nominal variables, some with high cardinality, are becoming increasingly common and need to be explored. Unfortunately, most existing visual exploration displays are designed to handle numeric variables only. When importing data sets with nominal values into such visualization tools, most solutions to date are rather simplistic. Often, techniques that map nominal values to numbers do not assign order or spacing among the values in a manner that conveys semantic relationships. Moreover, displays designed for nominal variables usually cannot handle high cardinality variables well. This paper addresses the problem of how to display nominal variables in general-purpose visual exploration tools designed for numeric variables. Specifically, we investigate (1) how to assign order and spacing among the nominal values, and (2) how to reduce the number of distinct values to display. We propose that nominal variables be pre-processed using a distance-quantification-classing (DQC) approach before being imported into a visual exploration tool. In the distance step, we identify a set of independent dimensions that can be used to calculate the distance between nominal values. In the quantification step, we use the independent dimensions and the distance information to assign order and spacing among the nominal values. In the classing step, we use results from the previous steps to determine which values within a variable are similar to each other and thus can be grouped together. Each step in the DQC approach can be accomplished by a variety of techniques. We extended the XmdvTool package to incorporate this approach. We evaluated our approach on several data sets using a variety of evaluation measures. visualization evaluation data visualisation clustering dimension reduction Ward, M.O. Rundensteiner, E.A. mathematics computing InfoVis visualization tools data visualization data sets Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 data compression nominal Rosario, G.E. Brown, D.C. software packages DQC approach XmdvTool package classing step clustering correspondence analysis dimension reduction distance step distance-quantification-classing nominal data nominal value mapping nominal variables norminal values numeric variables quantification step visual exploration displays nominal data correspondence analysis quantification classing infovis03--1249015 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Interactive hierarchical dimension ordering, spacing and filtering for exploration of high dimensional datasets. Large number of dimensions not only cause clutter in multi-dimensional visualizations, but also make it difficult for users to navigate the data space. Effective dimension management, such as dimension ordering, spacing and filtering, is critical for visual exploration of such datasets. Dimension ordering and spacing explicitly reveal dimension relationships in arrangement-sensitive multidimensional visualization techniques, such as parallel coordinates, star glyphs, and pixel-oriented techniques. They facilitate the visual discovery of patterns within the data. Dimension filtering hides some of the dimensions to reduce clutter while preserving the major information of the dataset. In this paper, we propose an interactive hierarchical dimension ordering, spacing and filtering approach, called DOSFA. DOSFA is based on dimension hierarchies derived from similarities among dimensions. It is scalable multi-resolution approach making dimensional management a tractable task. On the one hand, it automatically generates default settings for dimension ordering, spacing and filtering. On the other hand, it allows users to efficiently control all aspects of this dimension management process via visual interaction tools for dimension hierarchy manipulation. A case study visualizing a dataset containing over 200 dimensions reveals high dimensional visualization techniques. interaction case study parallel coordinates pixel data visualisation pattern clustering graphical user interfaces data mining Ward, M.O. Rundensteiner, E.A. visual exploration parallel coordinates hierarchy hierarchies InfoVis multidimensional visualization Peng, W. high dimensional datasets Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 multidimensional visualization multidimensional visualizations Wang, J. DOSFA data space navigation dimension filtering dimension hierarchies dimension hierarchy manipulation dimension management dimension ordering dimension spacing dimensional management high dimensional dataset exploration high dimensional datasets interactive hierarchical dimensions pixel-oriented techniques star glyphs visual interaction tools dimension ordering dimension spacing dimension filtering infovis03--1249014 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Dynamic visualization of transient data streams. We introduce two dynamic visualization techniques using multidimensional scaling to analyze transient data streams such as newswires and remote sensing imagery. While the time-sensitive nature of these data streams requires immediate attention in many applications, the unpredictable and unbounded characteristics of this information can potentially overwhelm many scaling algorithms that require a full re-computation for every update. We present an adaptive visualization technique based on data stratification to ingest stream information adaptively when influx rate exceeds processing rate. We also describe an incremental visualization technique based on data fusion to project new information directly onto a visualization subspace spanned by the singular vectors of the previously processed neighboring data. The ultimate goal is to leverage the value of legacy and new information and minimize re-processing of the entire dataset in full resolution. We demonstrate these dynamic visualization results using a newswire corpus and a remote sensing imagery sequence. data visualisation data mining Cowley, W. Thomas, J. Wong, P.C. Foote, H. InfoVis multidimensional scaling text visualization Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 Adams, D. remote sensing sensor fusion adaptive visualization data fusion data fusion-based visualization data stratification data stratification-based visualization dynamic visualization incremental visualization neighboring data newswires remote sensing imagery singular vectors transient data streams visualization subspace dynamic visualization text visualization remote sensing imagery transient data stream infovis03--1249010 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Visualizing evolving networks: minimum spanning trees versus pathfinder networks. Network evolution is an ubiquitous phenomenon in a wide variety of complex systems. There is an increasing interest in statistically modeling the evolution of complex networks such as small-world networks and scale-free networks. In this article, we address a practical issue concerning the visualizations of co-citation networks of scientific publications derived by two widely known link reduction algorithms, namely minimum spanning trees (MSTs) and pathfinder networks (PFNETs). Our primary goal is to identify the strengths and weaknesses of the two methods in fulfilling the need for visualizing evolving networks. Two criteria are derived for assessing visualizations of evolving networks in terms of topological properties and dynamical properties. We examine the animated visualization models of the evolution of botulinum toxin research in terms of its co-citation structure across a 58-year span (1945-2002). The results suggest that although high-degree nodes dominate the structure of MST models, such structures can be inadequate in depicting the essence of how the network evolves because MST removes potentially significant links from high-order shortest paths. In contrast, PFNET models clearly demonstrate their superiority in maintaining the cohesiveness of some of the most pivotal paths, which in turn make the growth animation more predictable and interpretable. We suggest that the design of visualization and modeling tools for network evolution should take the cohesiveness of critical paths into account. network data visualisation animation network visualization Chen, C. InfoVis citation analysis trees (mathematics) Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 Morris, S. solid modelling MST PFNET botulinum toxin research cocitation networks complex networks dynamical properties evolving network visualization growth animation high-degree nodes link reduction algorithms minimum spanning trees network evolution pathfinder networks scale-free networks scientific publications shortest paths small-world networks topological properties ubiquitous computing visualization assessment network evolution co-citation networks pathfinder networks minimum spanning trees infovis03--1249009 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on MoireGraphs: radial focus+context visualization and interaction for graphs with visual nodes. Graph and tree visualization techniques enable interactive exploration of complex relations while communicating topology. However, most existing techniques have not been designed for situations where visual information such as images is also present at each node and must be displayed. This paper presents MoireGraphs to address this need. MoireGraphs combine a new focus+context radial graph layout with a suite of interaction techniques (focus strength changing, radial rotation, level highlighting, secondary foci, animated transitions and node information) to assist in the exploration of graphs with visual nodes. The method is scalable to hundreds of displayed visual nodes. interaction graph graph layout data visualisation Ma, K.-L. Jankun-Kelly, T.J. information visualization information visualization radial InfoVis focus+context focus+context trees (mathematics) graph drawing Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 graphs visual information graph drawing MoireGraphs animated transitions communicating topology level highlighting node information radial focus+context interaction radial focus+context visualization radial graph layout radial rotation tree visualization visual nodes radial graph layout infovis03--1249008 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Edgelens: an interactive method for managing edge congestion in graphs. An increasing number of tasks require people to explore, navigate and search extremely complex data sets visualized as graphs. Examples include electrical and telecommunication networks, Web structures, and airline routes. The problem is that graphs of these real world data sets have many interconnected nodes, ultimately leading to edge congestion: the density of edges is so great that they obscure nodes, individual edges, and even the visual information beneath the graph. To address this problem we developed an interactive technique called EdgeLens. An EdgeLens interactively curves graph edges away for a person's focus attention without changing the node positions. This opens up sufficient space to disambiguate node and edge relationships and to see underlying information while still preserving node layout. Initially two methods of creating this interaction were developed and compared in a user study. The results of this study were used in the selection of a basic approach and the subsequent development of the EdgeLens. We then improved the EdgeLens through use of transparency and colour and by allowing multiple lenses to appear on the graph. interaction user study graph data visualisation interactive visualization information visualization information visualization InfoVis Carpendale, S. data visualization data sets air traffic graph layout interactive visualization Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 navigation navigation graphs visual information Wong, N. Greenberg, S. Edgelens Web structures airline routes distortion lens electrical networks graph edge congestion management graph layout individual edges interactive method interconnected nodes telecommunication networks distortion lens edge congestion infovis03--1249007 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Design choices when architecting visualizations. In this paper, we focus on some of the key design decisions we faced during the process of architecting a visualization system and present some possible choices, with their associated advantages and disadvantages. We frame this discussion within the context of Rivet, our general visualization environment designed for rapidly prototyping interactive, exploratory visualization tools for analysis. As we designed increasingly sophisticated visualizations, we needed to refine Rivet in order to be able to create these richer displays for larger and more complex data sets. The design decisions we discuss in this paper include: the internal data model, data access, semantic meta-data information the visualization can use to create effective visual decodings, the need for data transformations in a visualization tool, modular objects for flexibility, and the tradeoff between simplicity and expressiveness when providing methods for creating visualizations. data visualisation visual databases data transformations information visualization information visualization Tang, D. InfoVis data sets software architecture Stolte, C. Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 information systems visualization system Bosche, R. meta data Rivet data access design tradeoffs internal data model modular objects semantic meta-data information system architecture visual decodings visualization architecture visualization tool prototyping system architecture semantic meta-data data transformations design tradeoffs infovis03--1249006 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Exploring high-D spaces with multiform matrices and small multiples. We introduce an approach to visual analysis of multivariate data that integrates several methods from information visualization, exploratory data analysis (EDA), and geovisualization. The approach leverages the component-based architecture implemented in GeoVISTA Studio to construct a flexible, multiview, tightly (but generically) coordinated, EDA toolkit. This toolkit builds upon traditional ideas behind both small multiples and scatterplot matrices in three fundamental ways. First, we develop a general, multiform, bivariate matrix and a complementary multiform, bivariate small multiple plot in which different bivariate representation forms can be used in combination. We demonstrate the flexibility of this approach with matrices and small multiples that depict multivariate data through combinations of: scatterplots, bivariate maps, and space-filling displays. Second, we apply a measure of conditional entropy to (a) identify variables from a high-dimensional data set that are likely to display interesting relationships and (b) generate a default order of these variables in the matrix or small multiple display. Third, we add conditioning, a kind of dynamic query/filtering in which supplementary (undisplayed) variables are used to constrain the view onto variables that are displayed. Conditioning allows the effects of one or more well understood variables to be removed form the analysis, making relationships among remaining variables easier to explore. We illustrate the individual and combined functionality enabled by this approach through application to analysis of cancer diagnosis and mortality data and their associated covariates and risk factors. geovisualization high-dimensional data scatterplot data visualisation visual databases data analysis data mining matrix visual analysis information visualization dynamic query small multiples toolkit MacEachren, A.M. InfoVis scatterplot matrix small multiples Guo, D. geovisualization space-filling visualization Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 object-oriented programming geographic information systems multivariate data pattern recognition exploratory data analysis scatterplot Xiping, D. Hardisty, F. Lengerich, G. medical diagnostic computing EDA GeoVISTA Studio bivariate maps bivariate matrix bivariate representation bivarite small multiple plot cancer diagnosis component-based architecture conditional entropy default order geovisualization high-dimensional data set high-dimensional space exploration mortality data multiform matrices multiple display risk factors scatterplot matrices scatterplot matrix small multiples space-filling displays EDA bivariate map conditional entropy conditioning GeoVISTA Studio infovis03--1249005 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on A model of multi-scale perceptual organization in information graphics. We propose a new method for assessing the perceptual organization of information graphics, based on the premise that the visual structure of an image should match the structure of the data it is intended to convey. The core of our method is a new formal model of one type of perceptual structure, based on classical machine vision techniques for analyzing an image at multiple resolutions. The model takes as input an arbitrary grayscale image and returns a lattice structure describing the visual organization of the image. We show how this model captures several aspects of traditional design aesthetics, and we describe a software tool that implements the model to help designers analyze and refine visual displays. Our emphasis here is on demonstrating the model's potential as a design aid rather than as a description of human perception, but given its initial promise we propose a variety of ways in which the model could be extended and validated. Fisher, D. data visualisation graphical user interfaces Wattenberg, M. user interfaces visualization perception InfoVis aesthetics design methodology Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 scale space computer displays software tools software tool computer vision design aid formal model grayscale image human perception information graphics lattice structure machine vision multiple resolutions multiscale perceptual organization perceptual structure screen design software psychology user/machine systems visual displays visual organization visual structure perceptual organization scale space design methodology infovis03--1249004 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Smooth and efficient zooming and panning. Large 2D information spaces, such as maps, images, or abstract visualizations, require views at various level of detail: close ups to inspect details, overviews to maintain (literally) an overview. Users often switch between these views. We discuss how smooth animations from one view to another can be defined. To this end, a metric on the effect of simultaneous zooming and panning is defined, based on an estimate of the perceived velocity. Optimal is defined as smooth and efficient. Given the metric, these terms can be translated into a computational model, which is used to calculate an analytic solution for optimal animations. The model has two free parameters: animation speed and zoom/pan trade off. A user experiment to find good values for these is described. zooming overview data visualisation graphical user interfaces user interfaces experiment zoom animation InfoVis van Wijk, J.J. Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 computer animation navigation zooming software engineering navigation scale space Nuij, W.A.A. computational geometry image processing 2D information spaces abstract visualization animation speed computational model image visualization inspection techniques map visualization optimal animations panning perceived velocity scrolling smooth animations zooming panning scrolling scale space infovis03--1249013 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on A virtual workspace for hybrid multidimensional scaling algorithms. In visualising multidimensional data, it is well known that different types of algorithms to process them. Data sets might be distinguished according to volume, variable types and distribution, and each of these characteristics imposes constraints upon the choice of applicable algorithms for their visualization. Previous work has shown that a hybrid algorithmic approach can be successful in addressing the impact of data volume on the feasibility of multidimensional scaling (MDS). This suggests that hybrid combinations of appropriate algorithms might also successfully address other characteristics of data. This paper presents a system and framework in which a user can easily explore hybrid algorithms and the data flowing through them. Visual programming and a novel algorithmic architecture let the user semi-automatically define data flows and the co-ordination of multiple views. data visualisation multiple views multiple views InfoVis data structures multidimensional scaling computational complexity data sets visual programming multidimensional scaling Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 visual programming multidimensional data Chalmers, M. Ross, G. visual programmingHIVE MDS algorithmic architecture data flows data volume hybrid algorithm hybrid combinations variable distribution variable types virtual workspace data-flow hybrid algorithms complexity infovis03--1249021 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on An experimental evaluation of continuous semantic zooming in program. This paper presents the results of an experiment aimed at investigating how different methods of viewing visual programs affect users' understanding. The first two methods used traditional flat and semantic zooming models of program representation; the third is a new representation that uses semantic zooming combined with blending and proximity. The results of several search tasks performed by approximately 80 participants showed that the new method resulted in both faster and more accurate searches than the other methods. zooming evaluation data visualisation graphical user interfaces experiment InfoVis program visualisation Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 reverse engineering Summers, K.L. Goldsmith, T.E. Kubica, S. Caudell, T.P. continuous semantic zooming flat zooming human subjects testing program representation program visualization user understanding visual program languages visual programs program visualization human subjects testing visual program languages infovis03--1249024 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Compound brushing [dynamic data visualization]. This paper proposes a conceptual model called compound brushing for modeling the brushing techniques used in dynamic data visualization. In this approach, brushing techniques are modeled as higraphs with five types of basic entities: data, selection, device, renderer, and transformation. Using this model, a flexible visual programming tool is designed not only to configure/control various common types of brushing techniques currently used in dynamic data visualization, but also to investigate new brushing techniques. data visualisation graphical user interfaces brushing InfoVis brushing visual programming data visualization dynamic query Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 visual programming Chen, H. brushing techniques compound brushing device dynamic data visualization dynamic graphics dynamic query higraphs renderer selection transformation visual programming tool selection dynamic graphics higraph infovis03--1249030 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Using multilevel call matrices in large software projects. Traditionally, node link diagrams are the prime choice when it comes to visualizing software architectures. However, node link diagrams often fall short when used to visualize large graph structures. In this paper we investigate the use of call matrices as visual aids in the management of large software projects. We argue that call matrices have a number of advantages over traditional node link diagrams when the main object of interest is the link instead of the node. Matrix visualizations can provide stable and crisp layouts of large graphs and are inherently well suited for large multilevel visualizations because of their recursive structure. We discuss a number of visualization issues, using a very large software project currently under development at Philips Medical Systems as a running example. graph data visualisation graphical user interfaces matrix InfoVis van Ham, F. graph structures software architecture software visualization software visualization medical information systems program visualisation Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 screens (display) Philips Medical Systems large software projects matrix visualizations multilevel call matrices multilevel visualizations node-link diagram recursive structure visual aids multilevel visualization call matrix infovis03--1249011 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Multiscale visualization of small world networks. Many networks under study in Information Visualization are "small world" networks. These networks first appeared in the study social networks and were shown to be relevant models in other application domains such as software reverse engineering and biology. Furthermore, many of these networks actually have a multiscale nature: they can be viewed as a network of groups that are themselves small world networks. We describe a metric that has been designed in order to identify the weakest edges in a small world network leading to an easy and low cost filtering procedure that breaks up a graph into smaller and highly connected components. We show how this metric can be exploited through an interactive navigation of the network based on semantic zooming. Once the network is decomposed into a hierarchy of sub-networks, a user can easily find groups and subgroups of actors and understand their dynamics. small world networks multiscale graphs clustering metric semantic zooming social network graph navigation zooming hierarchy InfoVis Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 Auber, D. Chircota, Y. Jourdan, F. Melancon, G. infovis03--1249012 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Improving Hybrid MDS with Pivot-based Searching. An algorithm is presented for the visualisation of multidimensional abstract data, building on a hybrid model introduced at InfoVis 2002. The most computationally complex stage of the original model involved performing a nearest-neighbour search for every data item. The complexity of this phase has been reduced by treating all high-dimensional relationships as a set of discretised distances to a constant number of randomly selected pivot items. In improving this computational bottleneck, the complexity is reduced from O(NsqrtN) to O(N5/4). As well as documenting this improvement, the paper describes evaluation with a data set of 108000 14-dimensional items; a considerable increase on the size of data previously tested. Results illustrate that the reduction in complexity is reflected in significantly improved run times and that no negative impact is made upon the quality of layout produced. multidimensional scaling MDS spring models hybrid algorithms pivots near-neighbour search force directed placement evaluation InfoVis Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 Morrison, A. Chalmers, M. infovis03--1249017 10/19/2003 Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on Visualization of labeled data using linear transformations. We present a novel family of data-driven linear transformations, aimed at visualizing multivariate data in a low-dimensional space in a way that optimally preserves the structure of the data. The well-studied PCA and Fisher's LDA are shown to be special members in this family of transformations, and we demonstrate how to generalize these two methods such as to enhance their performance. Furthermore, our technique is the only one, to the best of our knowledge, that reflects in the resulting embedding both the data coordinates and pairwise similarities and/or dissimilarities between the data elements. Even more so, when information on the clustering (labeling) decomposition of the data is known, this information can be integrated in the linear transformation, resulting in embeddings that clearly show the separation between the clusters, as well as their intra-structure. All this make our technique very flexible and powerful, and let us cope with kinds of data that other techniques fail to describe properly. visualization dimensionality-reduction projection principal component analysis Fisher's linear discriminant analysis eigenprojection classification clustering InfoVis Information Visualization, 2003. INFOVIS 2003. IEEE Symposium on 2003 Koren, Y. Carmel, L. infovis04--1382900 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Evaluating a System for Interactive Exploration of Large, Hierarchically Structured Document Repositories. The InfoSky visual explorer is a system enabling users to interactively explore large, hierarchically structured document collections. Similar to a real-world telescope, InfoSky employs a planar graphical representation with variable magnification. Documents of similar content are placed close to each other and displayed as stars, while collections of documents at a particular level in the hierarchy are visualised as bounding polygons. Usability testing of an early prototype implementation of InfoSky revealed several design issues which prevented users from fully exploiting the power of the visual metaphor. Evaluation results have been incorporated into an advanced prototype, and another usability test has been conducted. A comparison of test results demonstrates enhanced system performance and points out promising directions for further work document evaluation usability hierarchy InfoVis navigation information visualization 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Andrews, K. knowledge management Granitzer, M. Kienreich, W. Sabol, V. Klieber, W. Voronoi document retrieval force-directed placement hierarchical repositories information management infovis04--1382901 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Metric-Based Network Exploration and Multiscale Scatterplot. We describe an exploratory technique based on the direct interaction with a 2D modified scatterplot computed from two different metrics calculated over the elements of a network. The scatterplot is transformed into an image by applying standard image processing techniques resulting into blurring effects. Segmentation of the image allow to easily select patches on the image as a way to extract subnetworks. We were inspired by the work of Wattenberg and Fisher [M. Wattenberg et al. (2003)] showing that the blurring process builds into a multiscale perceptual scheme, making this type of interaction intuitive to the user. We explain how the exploration of the network can be guided by the visual analysis of the blurred scatterplot and by its possible interpretations interaction network scatterplot clustering metrics InfoVis Chiricota, Y. 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on scatterplot Melancon, G. Jourdan, F. graph navigation blurring exploration filtering multiscale perceptual organization infovis04--1382902 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on A Knowledge Task-Based Framework for Design and Evaluation of Information Visualizations. The design and evaluation of most current information visualization systems descend from an emphasis on a user's ability to "unpack" the representations of data of interest and operate on them independently. Too often, successful decision-making and analysis are more a matter of serendipity and user experience than of intentional design and specific support for such tasks; although humans have considerable abilities in analyzing relationships from data, the utility of visualizations remains relatively variable across users, data sets, and domains. In this paper, we discuss the notion of analytic gaps, which represent obstacles faced by visualizations in facilitating higher-level analytic tasks, such as decision-making and learning. We discuss support for bridging the analytic gap, propose a framework for design and evaluation of information visualization systems, and demonstrate its use evaluation Stasko, J. evaluation InfoVis information visualization theory Amar, R. 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on framework analytic gap knowledge tasks infovis04--1382903 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Rethinking Visualization: A High-Level Taxonomy. We present the novel high-level visualization taxonomy. Our taxonomy classifies visualization algorithms rather than data. Algorithms are categorized based on the assumptions they make about the data being visualized; we call this set of assumptions the design model. Because our taxonomy is based on design models, it is more flexible than existing taxonomies and considers the user's conceptual model, emphasizing the human aspect of visualization. Design models are classified according to whether they are discrete or continuous and by how much the algorithm designer chooses display attributes such as spatialization, timing, colour, and transparency. This novel approach provides an alternative view of the visualization field that helps explain how traditional divisions (e.g., information and scientific visualization) relates and overlap, and that may inspire research ideas in hybrid visualization areas visualization Tory, M. classification taxonomy user model InfoVis taxonomy 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Moller, T. conceptual model design model infovis04--1382904 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Building Highly-Coordinated Visualizations in Improvise. Improvise is a fully-implemented system in which users build and browse multiview visualizations interactively using a simple shared-object coordination mechanism coupled with a flexible, expression-based visual abstraction language. By coupling visual abstraction with coordination, users gain precise control over how navigation and selection in the visualization affects the appearance of data in individual views. As a result, it is practical to build visualizations with more views and richer coordination in Improvise than in other visualization systems. Building and browsing activities are integrated in a single, live user interface that lets users alter visualizations quickly and incrementally during data exploration Weaver, C. navigation multiple views InfoVis exploratory visualization coordination 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on coordinated queries visual abstraction language infovis04--1382905 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on The InfoVis Toolkit. This article presents the InfoVis toolkit, designed to support the creation, extension and integration of advanced 2D information visualization components into interactive Java swing applications. The InfoVis toolkit provides specific data structures to achieve a fast action/feedback loop required by dynamic queries. It comes with a large set of components such as range sliders and tailored control panels required to control and configure the visualizations. These components are integrated into a coherent framework that simplifies the management of rich data structures and the design and extension of visualizations. Supported data structures currently include tables, trees and graphs. Supported visualizations include scatter plots, time series, parallel coordinates, treemaps, icicle trees, node-link diagrams for trees and graphs and adjacency matrices for graphs. All visualizations can use fisheye lenses and dynamic labeling. The InfoVis toolkit supports hardware acceleration when available through Agile2D, an implementation of the Java graphics API based on OpenGL, achieving speedups of 10 to 200 times. The article also shows how new visualizations can be added and extended to become components, enriching visualizations as well as general applications Fekete, J.-D. information visualization time series parallel coordinates hardware toolkit InfoVis fisheye 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on graphics integration toolkit infovis04--1382906 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Topological Fisheye Views for Visualizing Large Graphs. Graph drawing is a basic visualization tool. For graphs of up to hundreds of nodes and edges, there are many effective techniques available. At greater scale, data density and occlusion problems often negate its effectiveness. Conventional pan-and-zoom, and multiscale and geometric fisheye views are not fully satisfactory solutions to this problem. As an alternative, we describe a topological zooming method. It is based on the precomputation of a hierarchy of coarsened graphs, which are combined on the fly into renderings with the level of detail dependent on the distance from one or more foci. We also discuss a related distortion method that allows our technique to achieve constant information density displays zooming graph zoom hierarchy distortion InfoVis North, S. fisheye Koren, Y. occlusion 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on graph drawing Gansner, E. large graph visualization topological fisheye infovis04--1382907 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Matrix Zoom: A Visual Interface to Semi-External Graphs. In Web data, telecommunications traffic and in epidemiological studies, dense subgraphs correspond to subsets of subjects (i.e. users, patients) that share a collection of attributes values (i.e. accessed Web pages, email-calling patterns or disease diagnostic profiles). Visual and computational identification of these "clusters" becomes useful when domain experts desire to determine those factors of major influence in the formation of access and communication clusters or in the detection and contention of disease spread. With the current increases in graphic hardware capabilities and RAM sizes, it is more useful to relate graph sizes to the available screen real estate S and the amount of available RAM M, instead of the number of edges or nodes in the graph. We offer a visual interface that is parameterized by M and S and is particularly suited for navigation tasks that require the identification of subgraphs whose edge density is above certain threshold. This is achieved by providing a zoomable matrix view of the underlying data. This view is strongly coupled to a hierarchical view of the essential information elements present in the data domain. We illustrate the applicability of this work to the visual navigation of cancer incidence data and to an aggregated sample of phone call traffic graph matrix navigation hardware zoom InfoVis van Ham, F. graph visualization clustering Abello, J. 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on cancer data external memory algorithms hierarchy trees phone traffic infovis04--1382908 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Dynamic Drawing of Clustered Graphs. This paper presents an algorithm for drawing a sequence of graphs that contain an inherent grouping of their vertex set into clusters. It differs from previous work on dynamic graph drawing in the emphasis that is put on maintaining the clustered structure of the graph during incremental layout. The algorithm works online and allows arbitrary modifications to the graph. It is generic and can be implemented using a wide range of static force-directed graph layout tools. The paper introduces several metrics for measuring layout quality of dynamic clustered graphs. The performance of our algorithm is analyzed using these metrics. The algorithm has been successfully applied to visualizing mobile object software graph graph layout metrics InfoVis Tal, A. Frishman, Y. software visualization graph drawing 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on graph drawing dynamic layout mobile objects infovis04--1382909 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Interactive Visualization of Small World Graphs. Many real world graphs have small world characteristics, that is, they have a small diameter compared to the number of nodes and exhibit a local cluster structure. Examples are social networks, software structures, bibliographic references and biological neural nets. Their high connectivity makes both finding a pleasing layout and a suitable clustering hard. In this paper we present a method to create scalable, interactive visualizations of small world graphs, allowing the user to inspect local clusters while maintaining a global overview of the entire structure. The visualization method uses a combination of both semantical and geometrical distortions, while the layout is generated by a spring embedder algorithm using recently developed force model. We use a cross referenced database of 500 artists as a running example social cluster clustering overview database InfoVis van Ham, F. graph visualization clustering van Wijk, J.J. graph drawing 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on small world graphs infovis04--1382910 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Non-Euclidean Spring Embedders. We present a method by which force-directed algorithms for graph layouts can be generalized to calculate the layout of a graph in an arbitrary Riemannian geometry. The method relies on extending the Euclidean notions of distance, angle, and force-interactions to smooth nonEuclidean geometries via projections to and from appropriately chosen tangent spaces. In particular, we formally describe the calculations needed to extend such algorithms to hyperbolic and spherical geometries graph information visualization InfoVis graph drawing 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Kobourov, S.G. Wampler, K. force-directed algorithms hyperbolic space non-Euclidean geometry spherical space spring embedder infovis04--1382884 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on An Evaluation of Microarray Visualization Tools for Biological Insight. High-throughput experiments such as gene expression microarrays in the life sciences result in large datasets. In response, a wide variety of visualization tools have been created to facilitate data analysis. Biologists often face a dilemma in choosing the best tool for their situation. The tool that works best for one biologist may not work well for another due to differences in the type of insight they seek from their data. A primary purpose of a visualization tool is to provide domain-relevant insight into the data. Ideally, any user wants maximum information in the least possible time. In this paper we identify several distinct characteristics of insight that enable us to recognize and quantify it. Based on this, we empirically evaluate five popular microarray visualization tools. Our conclusions can guide biologists in selecting the best tool for their data, and computer scientists in developing and evaluating visualizations insight evaluation North, C. bioinformatics microarray data InfoVis empirical evaluation Saraiya, P. 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Duca, K. data visualization high throughput experiments insight infovis04--1382885 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on User Experiments with Tree Visualization Systems. This paper describes a comparative experiment with five well-known tree visualization systems, and Windows Explorer as a baseline system. Subjects performed tasks relating to the structure of a directory hierarchy, and to attributes of files and directories. Task completion times, correctness and user satisfaction were measured, and video recordings of subjects' interaction with the systems were made. Significant system and task type effects and an interaction between system and task type were found. Qualitative analyses of the video recordings were thereupon conducted to determine reasons for the observed differences, resulting in several findings and design recommendations as well as implications for future experiments with tree visualization systems interaction information visualization experiment hierarchy InfoVis 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Kobsa, A. accuracy design recommendations experimental comparison task performance user interaction user satisfaction infovis04--1382886 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on A Comparison of the Readability of Graphs Using Node-Link and Matrix-Based Representations. In this paper, we describe a taxonomy of generic graph related tasks and an evaluation aiming at assessing the readability of two representations of graphs: matrix-based representations and node-link diagrams. This evaluation bears on seven generic tasks and leads to important recommendations with regard to the representation of graphs according to their size and density. For instance, we show that when graphs are bigger than twenty vertices, the matrix-based visualization performs better than node-link diagrams on most tasks. Only path finding is consistently in favor of node-link diagrams throughout the evaluation Fekete, J.-D. evaluation graph matrix evaluation taxonomy Ghoniem, M. InfoVis 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Castagliola, P. visualization of graphs adjacency matrices node-link representation readability infovis04--1382887 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on GeoTime Information Visualization. Analyzing observations over time and geography is a common task but typically requires multiple, separate tools. The objective of our research has been to develop a method to visualize, and work with, the spatial interconnectedness of information over time and geography within a single, highly interactive 3D view. A novel visualization technique for displaying and tracking events, objects and activities within a combined temporal and geospatial display has been developed. This technique has been implemented as a demonstratable prototype called GeoTime in order to determine potential utility. Initial evaluations have been with military users. However, we believe the concept is applicable to a variety of government and business analysis tasks business geospatial Wright, W. Kapler, T. InfoVis interactive visualization 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on 3D visualization geospatial link analysis spatiotemporal visual data analysis infovis04--1382888 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on RecMap: Rectangular Map Approximations. In many application domains, data is collected and referenced by its geospatial location. Nowadays, different kinds of maps are used to emphasize the spatial distribution of one or more geospatial attributes. The nature of geospatial statistical data is the highly nonuniform distribution in the real world data sets. This has several impacts on the resulting map visualizations. Classical area maps tend to highlight patterns in large areas, which may, however, be of low importance. Cartographers and geographers used cartograms or value-by-area maps to address this problem long before computers were available. Although many automatic techniques have been developed, most of the value-by-area cartograms are generated manually via human interaction. In this paper, we propose a novel visualization technique for geospatial data sets called RecMap. Our technique approximates a rectangular partition of the (rectangular) display area into a number of map regions preserving important geospatial constraints. It is a fully automatic technique with explicit user control over all exploration constraints within the exploration process. Experiments show that our technique produces visualizations of geospatial data sets, which enhance the discovery of global and local correlations, and demonstrate its performance in a variety of applications interaction information visualization Keim, D.A. geospatial Sips, M. InfoVis geographic visualization Panse, C. 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Heilmann, R. database and data mining visualization infovis04--1382889 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on EZEL: a Visual Tool for Performance Assessment of Peer-to-Peer File-Sharing Network. In this paper we present EZEL, a visual tool we developed for the performance assessment of peer-to-peer file-sharing networks. We start by identifying the relevant data transferred in this kind of networks and the main performance assessment questions. Then we describe the visualization of data from two different points of view. First we take servers as focal points and we introduce a new technique, faded cushioning, which allows visualizing the same data from different perspectives. Secondly, we present the viewpoint of files, and we expose the correlations with the server stance via a special scatter plot. Finally, we discuss how our tool, based on the described techniques, is effective in the performance assessment of peer-to-peer file-sharing networks network InfoVis van Wijk, J.J. Voinea, L. Telea, A. 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on process visualization P2P file-sharing networks visualization distributed file systems visualization small displays infovis04--1382890 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on A History Mechanism for Visual Data Mining. A major challenge of current visualization and visual data mining (VDM) frameworks is to support users in the orientation in complex visual mining scenarios. An important aspect to increase user support and user orientation is to use a history mechanism that, first of all, provides un- and redoing functionality. In this paper, we present a new approach to include such history functionality into a VDM framework. Therefore, we introduce the theoretical background, outline design and implementation aspects of a history management unit, and conclude with a discussion showing the usefulness of our history management in a VDM framework history visualization data mining InfoVis Schumann, H. 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Kreuseler, M. Nocke, T. history undo/redo visual data mining infovis04--1382891 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Steerable, Progressive Multidimensional Scaling. Current implementations of multidimensional scaling (MDS), an approach that attempts to best represent data point similarity in a low-dimensional representation, are not suited for many of today's large-scale datasets. We propose an extension to the spring model approach that allows the user to interactively explore datasets that are far beyond the scale of previous implementations of MDS. We present MDSteer, a steerable MDS computation engine and visualization tool that progressively computes an MDS layout and handles datasets of over one million points. Our technique employs hierarchical data structures and progressive layouts to allow the user to steer the computation of the algorithm to the interesting areas of the dataset. The algorithm iteratively alternates between a layout stage in which a subselection of points are added to the set of active points affected by the MDS iteration, and a binning stage which increases the depth of the bin hierarchy and organizes the currently unplaced points into separate spatial regions. This binning strategy allows the user to select onscreen regions of the layout to focus the MDS computation into the areas of the dataset that are assigned to the selected bins. We show both real and common synthetic benchmark datasets with dimensionalities ranging from 3 to 300 and cardinalities of over one million points Munzner, T. hierarchy InfoVis multidimensional scaling 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Williams, M. dimensionality reduction infovis04--1382892 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on A Rank-by-Feature Framework for Unsupervised Multidimensional Data Exploration Using Low Dimensional Projections. Exploratory analysis of multidimensional data sets is challenging because of the difficulty in comprehending more than three dimensions. Two fundamental statistical principles for the exploratory analysis are (1) to examine each dimension first and then find relationships among dimensions, and (2) to try graphical displays first and then find numerical summaries (D.S. Moore, (1999). We implement these principles in a novel conceptual framework called the rank-by-feature framework. In the framework, users can choose a ranking criterion interesting to them and sort 1D or 2D axis-parallel projections according to the criterion. We introduce the rank-by-feature prism that is a color-coded lower-triangular matrix that guides users to desired features. Statistical graphs (histogram, boxplot, and scatterplot) and information visualization techniques (overview, coordination, and dynamic query) are combined to help users effectively traverse 1D and 2D axis-parallel projections, and finally to help them interactively find interesting features scatterplot overview Shneiderman, B. matrix information visualization dynamic query InfoVis color Seo, J. exploratory data analysis statistical graphics 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on dynamic query feature detection/selection infovis04--1382893 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Value and Relation Display for Interactive Exploration of High Dimensional Datasets. Traditional multidimensional visualization techniques, such as glyphs, parallel coordinates and scatterplot matrices, suffer from clutter at the display level and difficult user navigation among dimensions when visualizing high dimensional datasets. In this paper, we propose a new multidimensional visualization technique named a value and relation (VaR) display, together with a rich set of navigation and selection tools, for interactive exploration of datasets with up to hundreds of dimensions. By explicitly conveying the relationships among the dimensions of a high dimensional dataset, the VaR display helps users grasp the associations among dimensions. By using pixel-oriented techniques to present values of the data items in a condensed manner, the VaR display reveals data patterns in the dataset using as little screen space as possible. The navigation and selection tools enable users to interactively reduce clutter, navigate within the dimension space, and examine data value details within context effectively and efficiently. The VaR display scales well to datasets with large numbers of data items by employing sampling and texture mapping. A case study on a real dataset, as well as the VaR displays of multiple real datasets throughout the paper, reveals how our proposed approach helps users interactively explore high dimensional datasets with large numbers of data items Yang, J. case study scatterplot parallel coordinates pixel Ward, M.O. Rundensteiner, E.A. navigation Huang, S. InfoVis 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on high dimensional datasets Patro, A. Mehta, N. multi-dimensional visualization multi-dimensional scaling pixel-oriented infovis04--1382894 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Uncovering Clusters in Crowded Parallel Coordinates Visualizations. The one-to-one strategy of mapping each single data item into a graphical marker adopted in many visualization techniques has limited usefulness when the number of records and/or the dimensionality of the data set are very high. In this situation, the strong overlapping of graphical markers severely hampers the user's ability to identify patterns in the data from its visual representation. We tackle this problem here with a strategy that computes frequency or density information from the data set, and uses such information in parallel coordinates visualizations to filter out the information to be presented to the user, thus reducing visual clutter and allowing the analyst to observe relevant patterns in the data. The algorithms to construct such visualizations, and the interaction mechanisms supported, inspired by traditional image processing techniques such as grayscale manipulation and thresholding are also presented. We also illustrate how such algorithms can assist users to effectively identify clusters in very noisy large data sets interaction parallel coordinates filter information visualization InfoVis 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Artero, A.O. de Oliveira, M.C.F. Levkowitz, H. density-based visualization visual clustering visual data mining infovis04--1382895 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Clutter Reduction in Multi-Dimensional Data Visualization Using Dimension Reordering. Visual clutter denotes a disordered collection of graphical entities in information visualization. Clutter can obscure the structure present in the data. Even in a small dataset, clutter can make it hard for the viewer to find patterns, relationships and structure. In this paper, we define visual clutter as any aspect of the visualization that interferes with the viewer's understanding of the data, and present the concept of clutter-based dimension reordering. Dimension order is an attribute that can significantly affect a visualization's expressiveness. By varying the dimension order in a display, it is possible to reduce clutter without reducing information content or modifying the data in any way. Clutter reduction is a display-dependent task. In this paper, we follow a three-step procedure for four different visualization techniques. For each display technique, first, we determine what constitutes clutter in terms of display properties; then we design a metric to measure visual clutter in this display; finally we search for an order that minimizes the clutter in a display Ward, M.O. Rundensteiner, E.A. InfoVis 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Peng, W. multidimensional visualization dimension order visual clutter visual structure infovis04--1382896 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Time-Varying Data Visualization Using Information Flocking Boids. This research demonstrates how principles of self-organization and behavior simulation can be used to represent dynamic data evolutions by extending the concept of information flocking, originally introduced by Proctor & Winter (1998), to time-varying datasets. A rule-based behavior system continuously controls and updates the dynamic actions of individual, three-dimensional elements that represent the changing data values of reoccurring data objects. As a result, different distinguishable motion types emerge that are driven by local interactions between the spatial elements as well as the evolution of time-varying data values. Notably, this representation technique focuses on the representation of dynamic data alteration characteristics, or how reoccurring data objects change over time, instead of depicting the exact data values themselves. In addition, it demonstrates the potential of motion as a useful information visualization cue. The original information flocking approach is extended to incorporate time-varying datasets, live database querying, continuous data streaming, real-time data similarity evaluation, automatic shape generation and more stable flocking algorithms. Different experiments prove that information flocking is capable of representing short-term events as well as long-term temporal data evolutions of both individual and groups of time-dependent data objects. An historical stock market quote price dataset is used to demonstrate the algorithms and principles of time-varying information flocking evaluation database InfoVis 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Moere, A.V. 3D information visualization artificial life boids motion time-varying information visualization infovis04--1382897 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Artifacts of the Presence Era: Using Information Visualization to Create an Evocative Souvenir. We present Artifacts of the Presence Era, a digital installation that uses a geological metaphor to visualize the events in a physical space over time. The piece captures video and audio from a museum and constructs an impressionistic visualization of the evolving history in the space. Instead of creating a visualization tool for data analysis, we chose to produce a piece that functions as a souvenir of a particular time and place. We describe the design choices we made in creating this installation, the visualization techniques we developed, and the reactions we observed from users and the media. We suggest that the same approach can be applied to a more general set of visualization contexts, ranging from email archives to newsgroups conversations visualization history Viegas, F.B. history InfoVis 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Perry, E. Howe, E. Donath, J. public space infovis04--1382898 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Paint Inspired Color Mixing and Compositing for Visualization. Color is often used to convey information, and color compositing is often required while visualizing multiattribute information. This paper proposes an alternative method for color compositing. In order to present understandable color blending to the general public, several techniques are proposed. First, a paint-inspired RYB color space is used. In addition, noise patterns are employed to produce subregions of pure color within an overlapped region. We show examples to demonstrate the effectiveness of our technique for visualization Chen, B. InfoVis color 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Gossett, N. color mixing perception RYB infovis04--1382899 10/10/2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Expand-Ahead: A Space-Filling Strategy for Browsing Trees. Many tree browsers allow subtrees under a node to be collapsed or expanded, enabling the user to control screen space usage and selectively drill-down. However, explicit expansion of nodes can be tedious. Expand-ahead is a space-filling strategy by which some nodes are automatically expanded to fill available screen space, without expanding so far that nodes are shown at a reduced size or outside the viewport. This often allows a user exploring the tree to see further down the tree without the effort required in a traditional browser. It also means the user can sometimes drill-down a path faster, by skipping over levels of the tree that are automatically expanded for them. Expand-ahead differs from many detail-in-context techniques in that there is no scaling or distortion involved. We present 1D and 2D prototype implementations of expand-ahead, and identify various design issues and possible enhancements to our designs. Our prototypes support smooth, animated transitions between different views of a tree. We also present the results of a controlled experiment which show that, under certain conditions, users are able to drill-down faster with expand-ahead than without experiment distortion InfoVis McGuffin, M.J. focus+context Balakrishnan, R. 2004 Information Visualization, 2004. INFOVIS 2004. IEEE Symposium on Davison, G. adaptive user interface automatic expansion expandahead space filling tree browsing and navigation infovis05--1532122 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Baby names, visualization, and social data analysis. The Name Voyager, a Web based visualization of historical trends in baby naming, has proven remarkably popular. This paper discusses the interaction techniques it uses for smooth visual exploration of thousands of time series. We also describe design decisions behind the application and lessons learned in creating an application that makes do-it-yourself data mining popular. The prime lesson, it is hypothesized, is that an information visualization tool may be fruitfully viewed not as a tool but as part of an online social environment. In other words, to design a successful exploratory data analysis tool, one good strategy is to create a system that enables "social" data analysis interaction social time series Wattenberg, M. data mining InfoVis 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on infovis05--1532123 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on A sky dome visualisation for identification of astronomical orientations. It has long been known that ancient temples were frequently oriented along the cardinal directions or to certain points along the horizon where Sun or Moon rise or set on special days of the year. In the last decades, archaeologists have found evidence of even older building structures buried in the soil, with doorways that also appear to have distinct orientations. This paper presents a novel diagram combining archaeological maps with a folded-apart, flattened view of the whole sky, showing the local horizon and the daily paths of Sun, Moon and brighter stars. By use of this diagram, interesting groupings of astronomical orientation directions, e.g. to certain Sunrise and Sunset points could be identified, which were evidently used to mark certain days of the year. Orientations to a few significant stars very likely indicated the beginning of the agricultural year in the middle neolithic period InfoVis 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Groller, M.E. Zotti, G. archaeology astronomy data visualization infovis05--1532124 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Interactive visualization of genealogical graphs. The general problem of visualizing "family trees", or genealogical graphs, in 2D, is considered. A graph theoretic analysis is given, which identifies why genealogical graphs can be difficult to draw. This motivates some novel graphical representations, including one based on a dual tree, a subgraph formed by the union of two trees. Dual trees can be drawn in various styles, including an indented outline style, and allow users to browse general multitrees in addition to genealogical graphs, by transitioning between different dual tree views. A software prototype for such browsing is described, that supports smoothly animated transitions, automatic camera framing, rotation of subtrees, and a novel interaction technique for expanding or collapsing subtrees to any depth with a single mouse drag interaction graph InfoVis McGuffin, M.J. 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on graph drawing Balakrishnan, R. genealogy genealogies family trees kinship multitrees graph theory graph browsing and navigation infovis05--1532125 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on The visual code navigator: an interactive toolset for source code investigation. We present the Visual Code Navigator, a set of three interrelated visual tools that we developed for exploring large source code software projects from three different perspectives, or views: the syntactic view shows the syntactic constructs in the source code. The symbol view shows the objects a file makes available after compilation, such as function signatures, variables, and namespaces. The evolution view looks at different versions in a project lifetime of a number of selected source files. The views share one code model, which combines hierarchical syntax based and line based information from multiple source files versions. We render this code model using a visual model that extends the pixel-filling, space partitioning properties of shaded cushion treemaps with novel techniques. We discuss how our views allow users to interactively answer complex questions on various code elements by simple mouse clicks. We validate the efficiency and effectiveness of our toolset by an informal user study on the source code of VTK, a large, industry-size C++ code base user study pixel multiple views InfoVis treemap 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Voinea, L. Telea, A. Lommerse, G. Nossin, F. source code visualization pixel-filling displays source code analysis infovis05--1532126 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Vizster: visualizing online social networks. Recent years have witnessed the dramatic popularity of online social networking services, in which millions of members publicly articulate mutual "friendship" relations. Guided by ethnographic research of these online communities, we have designed and implemented a visualization system for playful end-user exploration and navigation of large scale online social networks. Our design builds upon familiar node link network layouts to contribute customized techniques for exploring connectivity in large graph structures, supporting visual search and analysis, and automatically identifying and visualizing community structures. Both public installation and controlled studies of the system provide evidence of the system's usability, capacity for facilitating discovery, and potential for fun and engaged social activity visualization social network graph usability navigation Heer, J. data mining InfoVis 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on graphs Boyd, D. social networks community exploration play infovis05--1532127 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on PRISAD: a partitioned rendering infrastructure for scalable accordion drawing. We present PRISAD, the first generic rendering infrastructure for information visualization applications that use the accordion drawing technique: rubber sheet navigation with guaranteed visibility for marked areas of interest. Our new rendering algorithms are based on the partitioning of screen space, which allows us to handle dense dataset regions correctly. The algorithms in previous work led to incorrect visual representations because of overculling, and to inefficiencies due to overdrawing multiple items in the same region. Our pixel based drawing infrastructure guarantees correctness by eliminating overculling, and improves rendering performance with tight bounds on overdrawing. PRITree and PRISeq are applications built on PRISAD, with the feature sets of TreeJuxtaposer and SequenceJuxtaposer, respectively. We describe our PRITree and PRISeq dataset traversal algorithms, which are used for efficient rendering, culling, and layout of datasets within the PRISAD framework. We also discuss PRITree node marking techniques, which offer order-of-magnitude improvements to both memory and time performance versus previous range storage and retrieval techniques. Our PRITree implementation features a five fold increase in rendering speed for nontrivial tree structures, and also reduces memory requirements in some real world datasets by up to eight times, so we are able to handle trees of several million nodes. PRISeq renders fifteen times faster and handles datasets twenty times larger than previous work. information visualization pixel Munzner, T. navigation InfoVis focus+context 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Slack, J. Hildebrand, K. real time rendering progressive rendering infovis05--1532128 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Voronoi treemaps. Treemaps are a well known method for the visualization of attributed hierarchical data. Previously proposed treemap layout algorithms are limited to rectangular shapes, which cause problems with the aspect ratio of the rectangles as well as with identifying the visualized hierarchical structure. The approach of Voronoi treemaps presented in this paper eliminates these problems through enabling subdivisions of and in polygons. Additionally, this allows for creating treemap visualizations within areas of arbitrary shape, such as triangles and circles, thereby enabling a more flexible adaptation of treemaps for a wider range of applications. information visualization InfoVis treemap treemap Deussen, O. Balzer, M. 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Voronoi treemaps hierarchies trees Voronoi tessellations infovis05--1532129 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Elastic hierarchies: combining treemaps and node-link diagrams. We investigate the use of elastic hierarchies for representing trees, where a single graphical depiction uses a hybrid mixture, or "interleaving", of more basic forms at different nodes of the tree. In particular, we explore combinations of node link and treemap forms, to combine the space efficiency of treemaps with the structural clarity of node link diagrams. A taxonomy is developed to characterize the design space of such hybrid combinations. A software prototype is described, which we used to explore various techniques for visualizing, browsing and interacting with elastic hierarchies, such as side by side overview and detail views, highlighting and rubber banding across views, visualization of multiple foci, and smooth animations across transitions. The paper concludes with a discussion of the characteristics of elastic hierarchies and suggestions for research on their properties and uses. overview taxonomy multiple views hierarchies InfoVis McGuffin, M.J. treemap treemap interaction techniques 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on trees interactive visualization Zhao, S. Chignell, M.H. elastic hierarchies node-link diagram hybrids combinations overview+detail infovis05--1532130 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Dig-CoLa: directed graph layout through constrained energy minimization. We describe a new method for visualization of directed graphs. The method combines constraint programming techniques with a high performance force directed placement (FDP) algorithm so that the directed nature of the graph is highlighted while useful properties of FDP - such as emphasis of symmetries and preservation of proximity relations - are retained. Our algorithm automatically identifies those parts of the digraph that contain hierarchical information and draws them accordingly. Additionally, those parts that do not contain hierarchy are drawn at the same quality expected from a nonhierarchical, undirected layout algorithm. An interesting application of our algorithm is directional multidimensional scaling (DMDS). DMDS deals with low dimensional embedding of multivariate data where we want to emphasize the overall flow in the data (e.g. chronological progress) along one of the axes. graph graph layout hierarchy InfoVis Dwyer, T. Koren, Y. 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on infovis05--1532131 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Dynamic visualization of graphs with extended labels. The paper describes a novel technique to visualize graphs with extended node and link labels. The lengths of these labels range from a short phrase to a full sentence to an entire paragraph and beyond. Our solution is different from all the existing approaches that almost always rely on intensive computational effort to optimize the label placement problem. Instead, we share the visualization resources with the graph and present the label information in static, interactive, and dynamic modes without the requirement for tackling the intractability issues. This allows us to reallocate the computational resources for dynamic presentation of real time information. The paper includes a user study to evaluate the effectiveness and efficiency of the visualization technique. user study information visualization graph Thomas, J. Wong, P.C. Foote, H. Mackey, P. InfoVis graph visualization 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Eagan, J. Perrine, K. graph label placement dynamic animation infovis05--1532132 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on An evaluation of content browsing techniques for hierarchical space-filling visualizations. Space-filling visualizations, such as the TreeMap, are well suited for displaying the properties of nodes in hierarchies. To browse the contents of the hierarchy, the primary mode of interaction is by drilling down through many successive layers. In this paper we introduce a distortion algorithm based on fisheye and continuous zooming techniques for browsing data in the TreeMap representation. The motivation behind the distortion approach is for assisting users to rapidly browse information displayed in the TreeMap without opening successive layers of the hierarchy. Two experiments were conducted to evaluate the new approach. In the first experiment (N=20) the distortion approach is compared to the drill down method. Results show that subjects are quicker and more accurate in locating targets of interest using the distortion method. The second experiment (N=12) evaluates the effectiveness of the two approaches in a task requiring context, we define as the context browsing task. The results show that subjects are quicker and more accurate in locating targets with the distortion technique in the context browsing task. interaction zooming evaluation experiment hierarchy hierarchies distortion InfoVis treemap focus+context Irani, P.P. fisheye 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on distortion space-filling visualization Shi, K. Li, B. browsing hierarchy navigation drill-down treemap semantic zooming infovis05--1532133 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Turning the bucket of text into a pipe. Many visual analysis tools operate on a fixed set of data. However, professional information analysts follow issues over a period of time and need to be able to easily add new documents to an ongoing exploration. Some analysts handle documents in a moving window of time, with new documents constantly added and old ones aging out. This paper describes both the user interaction and the technical implementation approach for a visual analysis system designed to support constantly evolving text collections. interaction information visualization text InfoVis 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Crow, V. Hetzler, E. Payne, D.A. Turner, A.E. dynamic visualization user interaction design real-time updating infovis05--1532134 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Visual correlation for situational awareness. We present a novel visual correlation paradigm for situational awareness (SA) and suggest its usage in a diverse set of applications that require a high level of SA. Our approach is based on a concise and scalable representation, which leads to a flexible visualization tool that is both clear and intuitive to use. Situational awareness is the continuous extraction of environmental information, its integration with previous knowledge to form a coherent mental picture, and the use of that picture in anticipating future events. In this paper we build on our previous work on visualization for network intrusion detection and show how that approach can be generalized to encompass a much broader class of SA systems. We first propose a generalization that is based on what we term, the w3 premise, namely that each event must have at least the what, when and where attributes. We also present a second generalization, which increases flexibility and facilitates complex visual correlations. Finally, we demonstrate the generality of our approaches by applying our visualization paradigm in a collection of diverse SA areas. visualization network awareness InfoVis 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Agutter, J. Livnat, Y. Moon, S. Foresti, S. situation awareness network intrusion infovis05--1532135 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Highlighting conflict dynamics in event data. We present a method for visual summary of bilateral conflict structures embodied in event data. Such data consists of actors linked by time stamped events, and may be extracted from various sources such as news reports and dossiers. When analyzing political events, it is of particular importance to be able to recognize conflicts and actors involved in them. By projecting actors into a conflict space, we are able to highlight the main opponents in a series of tens of thousands of events, and provide a graphic overview of the conflict structure. Moreover, our method allows for smooth animation of the dynamics of a conflict. overview text mining information visualization Brandes, U. Lerner, J. animation InfoVis 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Fleischer, D. event analysis time-dependent visualization infovis05--1532136 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Low-level components of analytic activity in information visualization. Existing system level taxonomies of visualization tasks are geared more towards the design of particular representations than the facilitation of user analytic activity. We present a set of ten low level analysis tasks that largely capture people's activities while employing information visualization tools for understanding data. To help develop these tasks, we collected nearly 200 sample questions from students about how they would analyze five particular data sets from different domains. The questions, while not being totally comprehensive, illustrated the sheer variety of analytic questions typically posed by users when employing information visualization systems. We hope that the presented set of tasks is useful for information visualization system designers as a kind of common substrate to discuss the relative analytic capabilities of the systems. Further, the tasks may provide a form of checklist for system designers. Stasko, J. evaluation design knowledge discovery InfoVis taxonomy 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Eagan, J. Amar, R. analytic activity infovis05--1532137 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Simple 3D glyphs for spatial multivariate data. We present an effort to evaluate the possible utility of a new type of 3D glyphs intended for visualizations of multivariate spatial data. They are based on results from vision research suggesting that our perception of metric 3D structure is distorted and imprecise relative to the actual scene before us (e.g., "metric 3D structure in visualizations" by M. Lind et al. (2003)); only a class of qualitative properties of the scene is perceived with accuracy. These properties are best characterized as being invariant over affine but not Euclidean transformations. They are related, but not identical to, the non-accidental properties (NAPs) described by Lowe in "perceptual organization and visual recognition" (1984) on which the notion of geons is based in "recognition by components - a theory of image understanding" by I. Biederman (1987). A large number of possible 3D glyphs for the visualization of spatial data can be constructed using such properties. One group is based on the local sign of surface curvature. We investigated these properties in a visualization experiment. The results are promising and the implications for visualization are discussed. theory perception experiment InfoVis multidimensional visualization perception 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Lind, M. Forsell, C. Seipel, S. 3D glyphs infovis05--1532138 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Revealing structure within clustered parallel coordinates displays. In order to gain insight into multivariate data, complex structures must be analysed and understood. Parallel coordinates is an excellent tool for visualizing this type of data but has its limitations. This paper deals with one of its main limitations - how to visualize a large number of data items without hiding the inherent structure they constitute. We solve this problem by constructing clusters and using high precision textures to represent them. We also use transfer functions that operate on the high precision textures in order to highlight different aspects of the cluster characteristics. Providing predefined transfer functions as well as the support to draw customized transfer functions makes it possible to extract different aspects of the data. We also show how feature animation can be used as guidance when simultaneously analysing several clusters. This technique makes it possible to visually represent statistical information about clusters and thus guides the user, making the analysis process more efficient. insight cluster parallel coordinates clustering Jern, M. animation InfoVis Johansson, J. Cooper, M. 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Ljung, P. parallel coordinates transfer function feature animation infovis05--1532139 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Parallel sets: visual analysis of categorical data. The discrete nature of categorical data makes it a particular challenge for visualization. Methods that work very well for continuous data are often hardly usable with categorical dimensions. Only few methods deal properly with such data, mostly because of the discrete nature of categorical data, which does not translate well into the continuous domains of space and color. Parallel sets is a new visualization method that adopts the layout of parallel coordinates, but substitutes the individual data points by a frequency based representation. This abstracted view, combined with a set of carefully designed interactions, supports visual data analysis of large and complex data sets. The technique allows efficient work with meta data, which is particularly important when dealing with categorical datasets. By creating new dimensions from existing ones, for example, the user can filter the data according to his or her current needs. We also present the results from an interactive analysis of CRM data using parallel sets. We demonstrate how the flexible layout eases the process of knowledge crystallization, especially when combined with a sophisticated interaction scheme. interaction parallel coordinates interaction categorical filter Kosara, R. InfoVis color categorical data Hauser, H. 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Bendix, F. meta information infovis05--1532140 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Multivariate glyphs for multi-object clusters. Aggregating items can simplify the display of huge quantities of data values at the cost of losing information about the attribute values of the individual items. We propose a distribution glyph, in both two- and three-dimensional forms, which specifically addresses the concept of how the aggregated data is distributed over the possible range of values. It is capable of displaying distribution, variability and extent information for up to four attributes at a time of multivariate, clustered data. User studies validate the concept, showing that both glyphs are just as good as raw data and the 3D glyph is better for answering some questions. information visualization InfoVis multivariate visualization 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Rheingans, P. glyph Chlan, E.B. distribution aggregated data infovis05--1532141 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on An interactive 3D integration of parallel coordinates and star glyphs. Parallel coordinates are a powerful method for visualizing multidimensional data but, when applied to large data sets, they become cluttered and difficult to read. Star glyphs, on the other hand, can be used to display either the attributes of a data item or the values across all items for a single attribute. Star glyphs may readily provide a quick impression; however, since the full data set require multiple glyphs, overall readings are more difficult. We present parallel glyphs, an interactive integration of the visual representations of parallel coordinates and star glyphs that utilizes the advantages of both representations to offset the disadvantages they have separately. We discuss the role of uniform and stepped colour scales in the visual comparison of non-adjacent items and star glyphs. Parallel glyphs provide capabilities for focus-in-context exploration using two types of lenses and interactions specific to the 3D space. parallel coordinates parallel coordinates InfoVis Carpendale, S. 3D visualization 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Fanea, E. Isenberg, T. parallel glyphs star glyphs multi-dimensional data sets infovis05--1532142 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Graph-theoretic scagnostics. We introduce Tukey and Tukey scagnostics and develop graph-theoretic methods for implementing their procedure on large datasets. visualization graph InfoVis Wilkinson, L. Anand, A. 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on statistical graphics Grossman, R. infovis05--1532143 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Visualizing coordination in situ. Exploratory visualization environments allow users to build and browse coordinated multiview visualizations interactively. As the number of views and amount of coordination increases, conceptualizing coordination structure becomes more and more important for successful data exploration. Integrated metavisualization is exploratory visualization of coordination and other interactive structure directly inside a visualization's own user interface. This paper presents a model of integrated metavisualization, describes the problem of capturing dynamic interface structure as visualizable data, and outlines three general approaches to integration. Metavisualization has been implemented in improvise, using views, lenses, and embedding to reveal the dynamic structure of its own highly coordinated visualizations. Weaver, C. linked views InfoVis exploratory visualization 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on software visualization coordination metavisualization infovis05--1532144 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Two-tone pseudo coloring: compact visualization for one-dimensional data. A new pseudo coloring technique for large scale one-dimensional datasets is proposed. For visualization of a large scale dataset, user interaction is indispensable for selecting focus areas in the dataset. However, excessive switching of the visualized image makes it difficult for the user to recognize overview/ detail and detail/ detail relationships. The goal of this research is to develop techniques for visualizing details as precisely as possible in overview display. In this paper, visualization of a one-dimensional but very large dataset is considered. The proposed method is based on pseudo coloring, however, each scalar value corresponds to two discrete colors. By painting with two colors at each value, users can read out the value precisely. This method has many advantages: it requires little image space for visualization; both the overview and details of the dataset are visible in one image without distortion; and implementation is very simple. Several application examples, such as meteorological observation data and train convenience evaluation data, show the effectiveness of the method. interaction evaluation overview distortion InfoVis focus+context 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on data density Saito, T. Miyamura, H.N. Yamamoto, M. Saito, H. Hoshiya, Y. Kaseda, T. pseudo color overview detail infovis05--1532145 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on A note on space-filling visualizations and space-filling curves. A recent line of treemap research has focused on layout algorithms that optimize properties such as stability, preservation of ordering information, and aspect ratio of rectangles. No ideal treemap layout algorithm has been found, and so it is natural to explore layouts that produce nonrectangular regions. This note describes a connection between space-filling visualizations and the mathematics of space-filling curves, and uses that connection to characterize a family of layout algorithms which produce nonrectangular regions but enjoy geometric continuity under changes to the data and legibility even for highly unbalanced trees. Wattenberg, M. InfoVis treemap 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on infovis05--1532146 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on An optimization-based approach to dynamic visual context management. We are building an intelligent multimodal conversation system to aid users in exploring large and complex data sets. To tailor to diverse user queries introduced during a conversation, we automate the generation of system responses, including both spoken and visual outputs. In this paper, we focus on the problem of visual context management, a process that dynamically updates an existing visual display to effectively incorporate new information requested by subsequent user queries. Specifically, we develop an optimization based approach to visual context management. Compared to existing approaches, which normally handle predictable visual context updates, our work offers two unique contributions. First, we provide a general computational framework that can effectively manage a visual context for diverse, unanticipated situations encountered in a user system conversation. Moreover, we optimize the satisfaction of both semantic and visual constraints, which otherwise are difficult to balance using simple heuristics. Second, we present an extensible representation model that uses feature based metrics to uniformly define all constraints. We have applied our work to two different applications and our evaluation has shown the promise of this work. evaluation Zhou, M.X. metrics Aggarwal, V. InfoVis Wen, Z. 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on intelligent multimodal interface visual context management automated generation of visualization visual momentum infovis05--1532147 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Adapting the cognitive walkthrough method to assess the usability of a knowledge domain visualization. The usability of knowledge domain visualization (KDViz) tools can be assessed at several levels. Cognitive walkthrough (CW) is a well known usability inspection method that focuses on how easily users can learn software through exploration. Typical applications of CW follow structured tasks where user goals and action sequences that lead to achievement of the goals are well defined. KDViz and other information visualization tools, however, are typically designed for users to explore data and user goals and actions are less well understood. In this paper, we describe how the traditional CW method may be adapted for assessing the usability of these systems. We apply the adapted version of CW to CiteSpace, a KDViz tool that uses bibliometric analyses to create visualizations of scientific literatures. We describe usability issues identified by the adapted CW and discuss how CiteSpace supported the completion of tasks, such as identifying research fronts, and the achievement of goals. Finally, we discuss improvements to the adapted CW and issues to be addressed before applying it to a wider range of KDViz tools. usability Chen, C. InfoVis 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Allendoerfer, K. Aluker, S. Panjwani, G. Proctor, J. Sturtz, D. Vukovic, M. cognitive walkthrough usability inspection methods bibliographic networks infovis05--1532148 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Importance-driven visualization layouts for large time series data. Time series are an important type of data with applications in virtually every aspect of the real world. Often a large number of time series have to be monitored and analyzed in parallel. Sets of time series may show intrinsic hierarchical relationships and varying degrees of importance among the individual time series. Effective techniques for visually analyzing large sets of time series should encode the relative importance and hierarchical ordering of the time series data by size and position, and should also provide a high degree of regularity in order to support comparability by the analyst. In this paper, we present a framework for visualizing large sets of time series. Based on the notion of inter time series importance relationships, we define a set of objective functions that space-filling layout schemes for time series data should obey. We develop an efficient algorithm addressing the identified problems by generating layouts that reflect hierarchy and importance based relationships in a regular layout with favorable aspect ratios. We apply our technique to a number of real world data sets including sales and stock data, and we compare our technique with an aspect ratio aware variant of the well known TreeMap algorithm. The examples show the advantages and practical usefulness of our layout algorithm. information visualization Keim, D.A. time series Schreck, T. Hao, M.C. Dayal, U. hierarchy InfoVis treemap 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on time series space-filling layout generation infovis05--1532149 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Temporal visualization of planning polygons for efficient partitioning of geo-spatial data. Partitioning of geo-spatial data for efficient allocation of resources such as schools and emergency health care services is driven by a need to provide better and more effective services. Partitioning of spatial data is a complex process that depends on numerous factors such as population, costs incurred in deploying or utilizing resources and target capacity of a resource. Moreover, complex data such as population distributions are dynamic i.e. they may change over time. Simple animation may not effectively show temporal changes in spatial data. We propose the use of three temporal visualization techniques -wedges, rings and time slices - to display the nature of change in temporal data in a single view. Along with maximizing resource utilization and minimizing utilization costs, a partition should also ensure the long term effectiveness of the plan. We use multi-attribute visualization techniques to highlight the strengths and identify the weaknesses of a partition. Comparative visualization techniques allow multiple partitions to be viewed simultaneously. Users can make informed decisions about how to partition geo spatial data by using a combination of our techniques for multi-attribute visualization, temporal visualization and comparative visualization. animation InfoVis spatial data 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Rheingans, P. Shanbhag, P. desJardins, M. temporal visualization time-dependent attributes multi-attribute visualization resource allocation infovis05--1532150 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Flow map layout. Cartographers have long used flow maps to show the movement of objects from one location to another, such as the number of people in a migration, the amount of goods being traded, or the number of packets in a network. The advantage of flow maps is that they reduce visual clutter by merging edges. Most flow maps are drawn by hand and there are few computer algorithms available. We present a method for generating flow maps using hierarchical clustering given a set of nodes, positions, and flow data between the nodes. Our techniques are inspired by graph layout algorithms that minimize edge crossings and distort node positions while maintaining their relative position to one another. We demonstrate our technique by producing flow maps for network traffic, census data, and trade data. network graph graph layout clustering Hanrahan, P. Xiao, L. InfoVis hierarchical clustering GIS 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Phan, D. Yeh, R. flow maps infovis05--1532151 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Visualization of graphs with associated timeseries data. The most common approach to support analysis of graphs with associated time series data include: overlay of data on graph vertices for one timepoint at a time by manipulating a visual property (e.g. color) of the vertex, along with sliders or some such mechanism to animate the graph for other timepoints. Alternatively, data from all the timepoints can be overlaid simultaneously by embedding small charts into graph vertices. These graph visualizations may also be linked to other visualizations (e.g., parallel co-ordinates) using brushing and linking. This paper describes a study performed to evaluate and rank graph+timeseries visualization options based on users' performance time and accuracy of responses on predefined tasks. The results suggest that overlaying data on graph vertices one timepoint at a time may lead to more accurate performance for tasks involving analysis of a graph at a single timepoint, and comparisons between graph vertices for two distinct timepoints. Overlaying data simultaneously for all the timepoints on graph vertices may lead to more accurate and faster performance for tasks involving searching for outlier vertices displaying different behavior than the rest of the graph vertices for all timepoints. Single views have advantage over multiple views on tasks that require topological information. Also, the number of attributes displayed on nodes has a non trivial influence on accuracy of responses, whereas the number of visualizations affect the performance time. graph North, C. time series multiple views brushing InfoVis color graph visualization 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Saraiya, P. Lee, P. data overlay time series data analysis usability experiments infovis05--1532152 10/23/2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Interactive Sankey diagrams. We present a system that allows users to interactively explore complex flow scenarios represented as Sankey diagrams. Our system provides an overview of the flow graph and allows users to zoom in and explore details on demand. The support for quantitative flow tracing across the flow graph as well as representations at different levels of detail facilitate the understanding of complex flow situations. The energy flow in a city serves as a sample scenario for our system. Different forms of energy are distributed within the city and they are transformed into heat, electricity, or other forms of energy. These processes are visualized and interactively explored. In addition our system can be used as a planning tool for the exploration of alternative scenarios by interactively manipulating different parameters in the energy flow network. network graph overview zoom InfoVis 2005 Information Visualization, 2005. INFOVIS 2005. IEEE Symposium on Riehmann, P. Hanfler, M. Froehlich, B. Sankey diagram flow diagram infovis06--4015416 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on ASK-GraphView: A Large Scale Graph Visualization System. We describe ASK-GraphView, a node-link-based graph visualization system that allows clustering and interactive navigation of large graphs, ranging in size up to 16 million edges. The system uses a scalable architecture and a series of increasingly sophisticated clustering algorithms to construct a hierarchy on an arbitrary, weighted undirected input graph. By lowering the interactivity requirements we can scale to substantially bigger graphs. The user is allowed to navigate this hierarchy in a top down manner by interactively expanding individual clusters. ASK-GraphView also provides facilities for filtering and coloring, annotation and cluster labeling. information visualization graph cluster clustering navigation hierarchy 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on van Ham, F. graph visualization Abello, J. Krishnan, N. graph clustering infovis06--4015417 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on MatrixExplorer: a Dual-Representation System to Explore Social Networks. MatrixExplorer is a network visualization system that uses two representations: node-link diagrams and matrices. Its design comes from a list of requirements formalized after several interviews and a participatory design session conducted with social science researchers. Although matrices are commonly used in social networks analysis, very few systems support the matrix-based representations to visualize and analyze networks. MatrixExplorer provides several novel features to support the exploration of social networks with a matrix-based representation, in addition to the standard interactive filtering and clustering functions. It provides tools to reorder (layout) matrices, to annotate and compare findings across different layouts and find consensus among several clusterings. MatrixExplorer also supports node-link diagram views which are familiar to most users and remain a convenient way to publish or communicate exploration results. Matrix and node-link representations are kept synchronized at all stages of the exploration process. social Fekete, J.-D. network clustering matrix 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on Henry Riche, N. node-link diagram interactive clustering consensus exploratory process matrix ordering matrix-based representations social networks visualization infovis06--4015418 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Visual Analysis of Multivariate State Transition Graphs. We present a new approach for the visual analysis of state transition graphs. We deal with multivariate graphs where a number of attributes are associated with every node. Our method provides an interactive attribute-based clustering facility. Clustering results in metric, hierarchical and relational data, represented in a single visualization. To visualize hierarchically structured quantitative data, we introduce a novel technique: the bar tree. We combine this with a node-link diagram to visualize the hierarchy and an arc diagram to visualize relational data. Our method enables the user to gain significant insight into large state transition graphs containing tens of thousands of nodes. We illustrate the effectiveness of our approach by applying it to a real-world use case. The graph we consider models the behavior of an industrial wafer stepper and contains 55,043 nodes and 289,443 edges. insight graph clustering hierarchy 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on graph visualization van Wijk, J.J. multivariate visualization interactive clustering Pretorius, A.J. finite state machines state spaces transition systems infovis06--4015419 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Balancing Systematic and Flexible Exploration of Social Networks. Social network analysis (SNA) has emerged as a powerful method for understanding the importance of relationships in networks. However, interactive exploration of networks is currently challenging because: (1) it is difficult to find patterns and comprehend the structure of networks with many nodes and links, and (2) current systems are often a medley of statistical methods and overwhelming visual output which leaves many analysts uncertain about how to explore in an orderly manner. This results in exploration that is largely opportunistic. Our contributions are techniques to help structural analysts understand social networks more effectively. We present SocialAction, a system that uses attribute ranking and coordinated views to help users systematically examine numerous SNA measures. Users can (1) flexibly iterate through visualizations of measures to gain an overview, filter nodes, and find outliers, (2) aggregate networks using link structure, find cohesive subgroups, and focus on communities of interest, and (3) untangle networks by viewing different link types separately, or find patterns across different link types using a matrix overview. For each operation, a stable node layout is maintained in the network visualization so users can make comparisons. SocialAction offers analysts a strategy beyond opportunism, as it provides systematic, yet flexible, techniques for exploring social networks. social network coordinated views overview Shneiderman, B. matrix filter 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on Perer, A. coordinated views exploratory data analysis social networks attribute ranking interactive graph visualization infovis06--4015420 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Multi-Scale Banking to 45 Degrees. In his text Visualizing Data, William Cleveland demonstrates how the aspect ratio of a line chart can affect an analyst's perception of trends in the data. Cleveland proposes an optimization technique for computing the aspect ratio such that the average absolute orientation of line segments in the chart is equal to 45 degrees. This technique, called banking to 45deg, is designed to maximize the discriminability of the orientations of the line segments in the chart. In this paper, we revisit this classic result and describe two new extensions. First, we propose alternate optimization criteria designed to further improve the visual perception of line segment orientations. Second, we develop multi-scale banking, a technique that combines spectral analysis with banking to 45deg. Our technique automatically identifies trends at various frequency scales and then generates a banked chart for each of these scales. We demonstrate the utility of our techniques in a range of visualization tools and analysis examples. text perception Heer, J. Agrawala, M. 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization banking to 45 degrees graphical perception line charts sparklines time series infovis06--4015421 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Measuring Data Abstraction Quality in Multiresolution Visualizations. Data abstraction techniques are widely used in multiresolution visualization systems to reduce visual clutter and facilitate analysis from overview to detail. However, analysts are usually unaware of how well the abstracted data represent the original dataset, which can impact the reliability of results gleaned from the abstractions. In this paper, we define two data abstraction quality measures for computing the degree to which the abstraction conveys the original dataset: the histogram difference measure and the nearest neighbor measure. They have been integrated within XmdvTool, a public-domain multiresolution visualization system for multivariate data analysis that supports sampling as well as clustering to simplify data. Several interactive operations are provided, including adjusting the data abstraction level, changing selected regions, and setting the acceptable data abstraction quality level. Conducting these operations, analysts can select an optimal data abstraction level. Also, analysts can compare different abstraction methods using the measures to see how well relative data density and outliers are maintained, and then select an abstraction method that meets the requirement of their analytic tasks. Yang, J. clustering overview Ward, M.O. Rundensteiner, E.A. 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on clustering sampling Cui, Q. metrics multiresolution visualization infovis06--4015422 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Enabling Automatic Clutter Reduction in Parallel Coordinate Plots. We have previously shown that random sampling is an effective clutter reduction technique and that a sampling lens can facilitate focus+context viewing of particular regions. This demands an efficient method of estimating the overlap or occlusion of large numbers of intersecting lines in order to automatically adjust the sampling rate within the lens. This paper proposes several ways for measuring occlusion in parallel coordinate plots. An empirical study into the accuracy and efficiency of the occlusion measures show that a probabilistic approach combined with a 'binning' technique is very fast and yet approaches the accuracy of the more expensive 'true' complete measurement. parallel coordinates 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on focus+context occlusion information visualization Ellis, G. Dix, A. occlusion sampling clutter density reduction lens overplotting random sampling infovis06--4015423 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Topographic Visualization of Prefix Propagation in the Internet. We propose a new metaphor for the visualization of prefixes propagation in the Internet. Such a metaphor is based on the concept of topographic map and allows to put in evidence the relative importance of the Internet Service Providers (ISPs) involved in the routing of the prefix. Based on the new metaphor we propose an algorithm for computing layouts and experiment with such algorithm on a test suite taken from the real Internet. The paper extends the visualization approach of the BGPlay service, which is an Internet routing monitoring tool widely used by ISP operators. experiment 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on graph drawing Cortese, P.F. Di Battista, G. Moneta, A. Patrignani, M. Pizzonia, M. interdomain routing internet visualization spring embedder infovis06--4015424 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Network Visualization by Semantic Substrates. Networks have remained a challenge for information visualization designers because of the complex issues of node and link layout coupled with the rich set of tasks that users present. This paper offers a strategy based on two principles: (1) layouts are based on user-defined semantic substrates, which are non-overlapping regions in which node placement is based on node attributes, (2) users interactively adjust sliders to control link visibility to limit clutter and thus ensure comprehensibility of source and destination. Scalability is further facilitated by user control of which nodes are visible. We illustrate our semantic substrates approach as implemented in NVSS 1.0 with legal precedent data for up to 1122 court cases in three regions with 7645 legal citations. network Shneiderman, B. information visualization 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on network visualization Aris, A. graphical user interface semantic substrate infovis06--4015425 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Hierarchical Edge Bundles: Visualization of Adjacency Relations in Hierarchical Data. A compound graph is a frequently encountered type of data set. Relations are given between items, and a hierarchy is defined on the items as well. We present a new method for visualizing such compound graphs. Our approach is based on visually bundling the adjacency edges, i.e., non-hierarchical edges, together. We realize this as follows. We assume that the hierarchy is shown via a standard tree visualization method. Next, we bend each adjacency edge, modeled as a B-spline curve, toward the polyline defined by the path via the inclusion edges from one node to another. This hierarchical bundling reduces visual clutter and also visualizes implicit adjacency edges between parent nodes that are the result of explicit adjacency edges between their respective child nodes. Furthermore, hierarchical edge bundling is a generic method which can be used in conjunction with existing tree visualization techniques. We illustrate our technique by providing example visualizations and discuss the results based on an informal evaluation provided by potential users of such visualizations. evaluation graph hierarchy 2006 tree visualization InfoVis Visualization and Computer Graphics, IEEE Transactions on graph visualization hierarchies network visualization node-link diagram edge aggregation treemap Holten, D. curves edge bundling edge concentration infovis06--4015426 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Visualization of Geo-spatial Point Sets via Global Shape Transformation and Local Pixel Placement. In many applications, data is collected and indexed by geo-spatial location. Discovering interesting patterns through visualization is an important way of gaining insight about such data. A previously proposed approach is to apply local placement functions such as PixelMaps that transform the input data set into a solution set that preserves certain constraints while making interesting patterns more obvious and avoid data loss from overplotting. In experience, this family of spatial transformations can reveal fine structures in large point sets, but it is sometimes difficult to relate those structures to basic geographic features such as cities and regional boundaries. Recent information visualization research has addressed other types of transformation functions that make spatially-transformed maps with recognizable shapes. These types of spatial-transformation are called global shape functions. In particular, cartogram-based map distortion has been studied. On the other hand, cartogram-based distortion does not handle point sets readily. In this study, we present a framework that allows the user to specify a global shape function and a local placement function. We combine cartogram-based layout (global shape) with PixelMaps (local placement), obtaining some of the benefits of each toward improved exploration of dense geo-spatial data sets. insight geographic Keim, D.A. pixel Sips, M. 2006 distortion InfoVis Visualization and Computer Graphics, IEEE Transactions on North, S. cartogram Panse, C. geo-spatial data pixel placement shape transformation infovis06--4015427 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Worldmapper: The World as YouA¢¯ve Never Seen it Before. This paper describes the Worldmapper project, which makes use of novel visualization techniques to represent a broad variety of social and economic data about the countries of the world. The goal of the project is to use the map projections known as cartograms to depict comparisons and relations between different territories, and its execution raises many interesting design challenges that were not all apparent at the outset. We discuss the approaches taken towards these challenges, some of which may have considerably broad application. We conclude by commenting on the positive initial response to the Worldmapper images published on the Web, which we believe is due, at least in part, to the particular effectiveness of the cartogram as a tool for communicating quantitative geographic data. social geographic 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on geographic visualization data visualization cartogram Dorling, D. Barford, A. Newman, M. computer graphics social visualization Worldmapper infovis06--4015428 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Spatial Analysis of News Sources. People in different places talk about different things. This interest distribution is reflected by the newspaper articles circulated in a particular area. We use data from our large-scale newspaper analysis system (Lydia) to make entity datamaps, a spatial visualization of the interest in a given named entity. Our goal is to identify entities which display regional biases. We develop a model of estimating the frequency of reference of an entity in any given city from the reference frequency centered in surrounding cities, and techniques for evaluating the spatial significance of this distribution. 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on geographic visualization Li, X. GIS Mehler, A. Bao, Y. Wang, Y. Skiena, S. information analytics newspapers spidering text and document visualization WWW data visualization infovis06--4015429 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Dynamic Map Labeling. We address the problem of filtering, selecting and placing labels on a dynamic map, which is characterized by continuous zooming and panning capabilities. This consists of two interrelated issues. The first is to avoid label popping and other artifacts that cause confusion and interrupt navigation, and the second is to label at interactive speed. In most formulations the static map labeling problem is NP-hard, and a fast approximation might have O(n log n) complexity. Even this is too slow during interaction, when the number of labels shown can be several orders of magnitude less than the number in the map. In this paper we introduce a set of desiderata for "consistent" dynamic map labeling, which has qualities desirable for navigation. We develop a new framework for dynamic labeling that achieves the desiderata and allows for fast interactive display by moving all of the selection and placement decisions into the preprocessing phase. This framework is general enough to accommodate a variety of selection and placement algorithms. It does not appear possible to achieve our desiderata using previous frameworks. Prior to this paper, there were no formal models of dynamic maps or of dynamic labels; our paper introduces both. We formulate a general optimization problem for dynamic map labeling and give a solution to a simple version of the problem. The simple version is based on label priorities and a versatile and intuitive class of dynamic label placements we call "invariant point placements". Despite these restrictions, our approach gives a useful and practical solution. Our implementation is incorporated into the G-Vis system which is a full-detail dynamic map of the continental USA. This demo is available through any browser. interaction zooming navigation 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on GIS Been, K. Daiches, E. Yap, C. HCI map labeling computational cartography dynamic maps human-computer interface label consistency label filtering label placement label selection preprocessing realtime infovis06--4015430 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Visualization of Barrier Tree Sequences. Dynamical models that explain the formation of spatial structures of RNA molecules have reached a complexity that requires novel visualization methods that help to analyze the validity of these models. We focus on the visualization of so-called folding landscapes of a growing RNA molecule. Folding landscapes describe the energy of a molecule as a function of its spatial configuration; thus they are huge and high dimensional. Their most salient features, however, are encapsulated by their so-called barrier tree that reflects the local minima and their connecting saddle points. For each length of the growing RNA chain there exists a folding landscape. We visualize the sequence of folding landscapes by an animation of the corresponding barrier trees. To generate the animation, we adapt the foresight layout with tolerance algorithm for general dynamic graph layout problems. Since it is very general, we give a detailed description of each phase: constructing a supergraph for the trees, layout of that supergraph using a modified DOT algorithm, and presentation techniques for the final animation. graph graph layout Scheuermann, G. animation 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on Heine, C. Stadler, P.F. graph drawing Flamm, C. Hofacker, I.L. RNA folding barrier tree dynamic graph energy landscape fitness landscape infovis06--4015431 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Visualizing Business Data with Generalized Treemaps. Business data is often presented using simple business graphics. These familiar visualizations are effective for providing overviews, but fall short for the presentation of large amounts of detailed information. Treemaps can provide such detail, but are often not easy to understand. We present how standard treemap algorithms can be adapted such that the results mimic familiar business graphics. Specifically, we present the use of different layout algorithms per level, a number of variations of the squarified algorithm, the use of variable borders, and the use of non-rectangular shapes. The combined use of these leads to histograms, pie charts and a variety of other styles. business 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization treemap treemap van Wijk, J.J. hierarchical data Vliegen, R. van der Linden, E.-J. business graphics infovis06--4015432 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on FacetMap: A Scalable Search and Browse Visualization. The dominant paradigm for searching and browsing large data stores is text-based: presenting a scrollable list of search results in response to textual search term input. While this works well for the Web, there is opportunity for improvement in the domain of personal information stores, which tend to have more heterogeneous data and richer metadata. In this paper, we introduce FacetMap, an interactive, query-driven visualization, generalizable to a wide range of metadata-rich data stores. FacetMap uses a visual metaphor for both input (selection of metadata facets as filters) and output. Results of a user study provide insight into tradeoffs between FacetMap's graphical approach and the traditional text-oriented approach. user study Czerwinski, M. insight text Robertson, G. 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on Smith, G. Tan, D.S. Meyers, B.R. graphical visualization faceted metadata interactive information retrieval infovis06--4015433 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Visual Exploration of Complex Time-Varying Graphs. Many graph drawing and visualization algorithms, such as force-directed layout and line-dot rendering, work very well on relatively small and sparse graphs. However, they often produce extremely tangled results and exhibit impractical running times for highly non-planar graphs with large edge density. And very few graph layout algorithms support dynamic time-varying graphs; applying them independently to each frame produces distracting temporally incoherent visualizations. We have developed a new visualization technique based on a novel approach to hierarchically structuring dense graphs via stratification. Using this structure, we formulate a hierarchical force-directed layout algorithm that is both efficient and produces quality graph layouts. The stratification of the graph also allows us to present views of the data that abstract away many small details of its structure. Rather than displaying all edges and nodes at once, resulting in a convoluted rendering, we present an interactive tool that filters edges and nodes using the graph hierarchy and allows users to drill down into the graph for details. Our layout algorithm also accommodates time-varying graphs in a natural way, producing a temporally coherent animation that can be used to analyze and extract trends from dynamic graph data. For example, we demonstrate the use of our method to explore financial correlation data for the U.S. stock market in the period from 1990 to 2005. The user can easily analyze the time-varying correlation graph of the market, uncovering information such as market sector trends, representative stocks for portfolio construction, and the interrelationship of stocks over time. graph bioinformatics financial data visualization 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on time series data hierarchy visualization Garland, M. Kumar, G. graph and network visualization infovis06--4015434 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Smashing Peacocks Further: Drawing Quasi-Trees from Biconnected Components. Quasi-trees, namely graphs with tree-like structure, appear in many application domains, including bioinformatics and computer networks. Our new SPF approach exploits the structure of these graphs with a two-level approach to drawing, where the graph is decomposed into a tree of biconnected components. The low-level biconnected components are drawn with a force-directed approach that uses a spanning tree skeleton as a starting point for the layout. The higher-level structure of the graph is a true tree with meta-nodes of variable size that contain each biconnected component. That tree is drawn with a new area-aware variant of a tree drawing algorithm that handles high-degree nodes gracefully, at the cost of allowing edge-node overlaps. SPF performs an order of magnitude faster than the best previous approaches, while producing drawings of commensurate or improved quality. network graph high-dimensional data Munzner, T. 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on Archambault, D. Auber, D. graph and network visualization Quasi-Tree infovis06--4015435 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on IPSep-CoLa: An Incremental Procedure for Separation Constraint Layout of Graphs. We extend the popular force-directed approach to network (or graph) layout to allow separation constraints, which enforce a minimum horizontal or vertical separation between selected pairs of nodes. This simple class of linear constraints is expressive enough to satisfy a wide variety of application-specific layout requirements, including: layout of directed graphs to better show flow; layout with non-overlapping node labels; and layout of graphs with grouped nodes (called clusters). In the stress majorization force-directed layout process, separation constraints can be treated as a quadratic programming problem. We give an incremental algorithm based on gradient projection for efficiently solving this problem. The algorithm is considerably faster than using generic constraint optimization techniques and is comparable in speed to unconstrained stress majorization. We demonstrate the utility of our technique with sample data from a number of practical applications including gene-activation networks, terrorist networks and visualization of high-dimensional data. interaction user study usability scatterplot overview navigation database zoom 2006 distortion InfoVis Visualization and Computer Graphics, IEEE Transactions on Dwyer, T. graph drawing layout multidimensional scaling Marriott, K. constraints force-directed algorithms stress majorization fisheye Koren, Y. infovis06--4015436 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on User Interaction with Scatterplots on Small Screens - A Comparative Evaluation of Geometric-Semantic Zoom and Fisheye Distortion. Existing information-visualization techniques that target small screens are usually limited to exploring a few hundred items. In this article we present a scatterplot tool for Personal Digital Assistants that allows the handling of many thousands of items. The application's scalability is achieved by incorporating two alternative interaction techniques: a geometric-semantic zoom that provides smooth transition between overview and detail, and a fisheye distortion that displays the focus and context regions of the scatterplot in a single view. A user study with 24 participants was conducted to compare the usability and efficiency of both techniques when searching a book database containing 7500 items. The study was run on a pen-driven Wacom board simulating a PDA interface. While the results showed no significant difference in task-completion times, a clear majority of 20 users preferred the fisheye view over the zoom interaction. In addition, other dependent variables such as user satisfaction and subjective rating of orientation and navigation support revealed a preference for the fisheye distortion. These findings partly contradict related research and indicate that, when using a small screen, users place higher value on the ability to preserve navigational context than they do on the ease of use of a simplistic, metaphor-based interaction style. interaction evaluation overview experiment zoom 2006 distortion InfoVis Visualization and Computer Graphics, IEEE Transactions on small multiples focus+context fisheye fisheye zoom Buering, T. Gerken, J. Reiterer, H. PDA small screen scatterplot infovis06--4015437 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on The Perceptual Scalability of Visualization. Larger, higher resolution displays can be used to increase the scalability of information visualizations. But just how much can scalability increase using larger displays before hitting human perceptual or cognitive limits? Are the same visualization techniques that are good on a single monitor also the techniques that are best when they are scaled up using large, high-resolution displays? To answer these questions we performed a controlled experiment on user performance time, accuracy, and subjective workload when scaling up data quantity with different space-time-attribute visualizations using a large, tiled display. Twelve college students used small multiples, embedded bar matrices, and embedded time-series graphs either on a 2 megapixel (Mp) display or with data scaled up using a 32 Mp tiled display. Participants performed various overview and detail tasks on geospatially-referenced multidimensional time-series data. Results showed that current designs are perceptually scalable because they result in a decrease in task completion time when normalized per number of data attributes along with no decrease in accuracy. It appears that, for the visualizations selected for this study, the relative comparison between designs is generally consistent between display sizes. However, results also suggest that encoding is more important on a smaller display while spatial grouping is more important on a larger display. Some suggestions for designers are provided based on our experience designing visualizations for large displays. North, C. overview experiment 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization small multiples empirical evaluation Yost, B. large displays infovis06--4015438 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Complex Logarithmic Views for Small Details in Large Contexts. Commonly known detail in context techniques for the two-dimensional Euclidean space enlarge details and shrink their context using mapping functions that introduce geometrical compression. This makes it difficult or even impossible to recognize shapes for large differences in magnification factors. In this paper we propose to use the complex logarithm and the complex root functions to show very small details even in very large contexts. These mappings are conformal, which means they only locally rotate and scale, thus keeping shapes intact and recognizable. They allow showing details that are orders of magnitude smaller than their surroundings in combination with their context in one seamless visualization. We address the utilization of this universal technique for the interaction with complex two-dimensional data considering the exploration of large graphs and other examples. interaction interaction 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on Deussen, O. Balzer, M. Bottger, J. detail in context analytic functions complex logarithm conformal mappings infovis06--4015439 10/29/2006 Visualization and Computer Graphics, IEEE Transactions on Software Design Patterns for Information Visualization. Despite a diversity of software architectures supporting information visualization, it is often difficult to identify, evaluate, and re-apply the design solutions implemented within such frameworks. One popular and effective approach for addressing such difficulties is to capture successful solutions in design patterns, abstract descriptions of interacting software components that can be customized to solve design problems within a particular context. Based upon a review of existing frameworks and our own experiences building visualization software, we present a series of design patterns for the domain of information visualization. We discuss the structure, context of use, and interrelations of patterns spanning data representation, graphics, and interaction. By representing design knowledge in a reusable form, these patterns can be used to facilitate software design, implementation, and evaluation, and improve developer education and communication. interaction evaluation education information visualization Heer, J. Agrawala, M. 2006 InfoVis Visualization and Computer Graphics, IEEE Transactions on design patterns object-oriented programming software engineering infovis07--4376129 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Visual Analysis of Network Traffic for Resource Planning, Interactive Monitoring, and Interpretation of Security Threats. The Internet has become a wild place: malicious code is spread on personal computers across the world, deploying botnets ready to attack the network infrastructure. The vast number of security incidents and other anomalies overwhelms attempts at manual analysis, especially when monitoring service provider backbone links. We present an approach to interactive visualization with a case study indicating that interactive visualization can be applied to gain more insight into these large data sets. We superimpose a hierarchy on IP address space, and study the suitability of Treemap variants for each hierarchy level. Because viewing the whole IP hierarchy at once is not practical for most tasks, we evaluate layout stability when eliding large parts of the hierarchy, while maintaining the visibility and ordering of the data of interest. insight network Keim, D.A. case study 2007 security hierarchy Mansmann, F. network security InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization treemap North, S. treemap Rexroad, B. Sheleheda, D. network monitoring infovis07--4376130 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on AdaptiviTree: Adaptive Tree Visualization for Tournament-Style Brackets. Online pick'em games, such as the recent NCAA college basketball March Madness tournament, form a large and rapidly growing industry. In these games, players make predictions on a tournament bracket that defines which competitors play each other and how they proceed toward a single champion. Throughout the course of the tournament, players monitor the brackets to track progress and to compare predictions made by multiple players. This is often a complex sense making task. The classic bracket visualization was designed for use on paper and utilizes an incrementally additive system in which the winner of each match-up is rewritten in the next round as the tournament progresses. Unfortunately, this representation requires a significant amount of space and makes it relatively difficult to get a quick overview of the tournament state since competitors take arbitrary paths through the static bracket. In this paper, we present AdaptiviTree, a novel visualization that adaptively deforms the representation of the tree and uses its shape to convey outcome information. AdaptiviTree not only provides a more compact and understandable representation, but also allows overlays that display predictions as well as other statistics. We describe results from a lab study we conducted to explore the efficacy of AdaptiviTree, as well as from a deployment of the system in a recent real-world sports tournament. Lee, B. overview statistics Robertson, G. 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on Smith, G. Tan, D.S. online fantasy sports adaptive tree visualization bracket picks tournament infovis07--4376131 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on ManyEyes: a Site for Visualization at Internet Scale. We describe the design and deployment of Many Eyes, a public Web site where users may upload data, create interactive visualizations, and carry on discussions. The goal of the site is to support collaboration around visualizations at a large scale by fostering a social style of data analysis in which visualizations not only serve as a discovery tool for individuals but also as a medium to spur discussion among users. To support this goal, the site includes novel mechanisms for end-user creation of visualizations and asynchronous collaboration around those visualizations. In addition to describing these technologies, we provide a preliminary report on the activity of our users. collaboration social Wattenberg, M. Viegas, F.B. visualization 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on World Wide Web van Ham, F. McKeon, M. Kriss, J. communication-minded visualization social data analysis social software infovis07--4376132 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Scented Widgets: Improving Navigation Cues with Embedded Visualizations. This paper presents scented widgets, graphical user interface controls enhanced with embedded visualizations that facilitate navigation in information spaces. We describe design guidelines for adding visual cues to common user interface widgets such as radio buttons, sliders, and combo boxes and contribute a general software framework for applying scented widgets within applications with minimal modifications to existing source code. We provide a number of example applications and describe a controlled experiment which finds that users exploring unfamiliar data make up to twice as many unique discoveries using widgets imbued with social navigation data. However, these differences equalize as familiarity with the data increases. social navigation experiment 2007 Heer, J. Agrawala, M. InfoVis Visualization and Computer Graphics, IEEE Transactions on social data analysis information visualization social navigation Willett, W. information foraging user interface toolkits infovis07--4376133 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Show Me: Automatic Presentation for Visual Analysis. This paper describes Show Me, an integrated set of user interface commands and defaults that incorporate automatic presentation into a commercial visual analysis system called Tableau. A key aspect of Tableau is VizQL, a language for specifying views, which is used by Show Me to extend automatic presentation to the generation of tables of views (commonly called small multiple displays). A key research issue for the commercial application of automatic presentation is the user experience, which must support the flow of visual analysis. User experience has not been the focus of previous research on automatic presentation. The Show Me user experience includes the automatic selection of mark types, a command to add a single field to a view, and a pair of commands to build views for multiple fields. Although the use of these defaults and commands is optional, user interface logs indicate that Show Me is used by commercial users. visual analysis Hanrahan, P. small multiples 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on Mackinlay, J.D. Stolte, C. data visualization automatic presentation best practices graphic design infovis07--4376134 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Casual Information Visualization: Depictions of Data in Everyday Life. Information visualization has often focused on providing deep insight for expert user populations and on techniques for amplifying cognition through complicated interactive visual models. This paper proposes a new subdomain for infovis research that complements the focus on analytic tasks and expert use. Instead of work-related and analytically driven infovis, we propose casual information visualization (or casual infovis) as a complement to more traditional infovis domains. Traditional infovis systems, techniques, and methods do not easily lend themselves to the broad range of user populations, from expert to novices, or from work tasks to more everyday situations. We propose definitions, perspectives, and research directions for further investigations of this emerging subfield. These perspectives build from ambient information visualization (Skog et al., 2003), social visualization, and also from artistic work that visualizes information (Viegas and Wattenberg, 2007). We seek to provide a perspective on infovis that integrates these research agendas under a coherent vocabulary and framework for design. We enumerate the following contributions. First, we demonstrate how blurry the boundary of infovis is by examining systems that exhibit many of the putative properties of infovis systems, but perhaps would not be considered so. Second, we explore the notion of insight and how, instead of a monolithic definition of insight, there may be multiple types, each with particular characteristics. Third, we discuss design challenges for systems intended for casual audiences. Finally we conclude with challenges for system evaluation in this emerging subfield. insight social evaluation Stasko, J. evaluation cognition 2007 design InfoVis Visualization and Computer Graphics, IEEE Transactions on Pousman, Z. Mateas, M. casual information visualization ambient infovis editorial social infovis infovis07--4376135 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Geographically Weighted Visualization: Interactive Graphics for Scale-Varying Exploratory Analysis. We introduce a series of geographically weighted (GW) interactive graphics, or geowigs, and use them to explore spatial relationships at a range of scales. We visually encode information about geographic and statistical proximity and variation in novel ways through gw-choropleth maps, multivariate gw-boxplots, gw-shading and scalograms. The new graphic types reveal information about GW statistics at several scales concurrently. We impement these views in prototype software containing dynamic links and GW interactions that encourage exploration and refine them to consider directional geographies. An informal evaluation uses interactive GW techniques to consider Guerry's dataset of 'moral statistics', casting doubt on correlations originally proposed through visual analysis, revealing new local anomalies and suggesting multivariate geographic relationships. Few attempts at visually synthesising geography with multivariate statistical values at multiple scales have been reported. The geowigs proposed here provide informative representations of multivariate local variation, particularly when combined with interactions that coordinate views and result in gw-shading. We argue that they are widely applicable to area and point-based geographic data and provide a set of methods to support visual analysis using GW statistics through which the effects of geography can be explored at multiple scales. geographic evaluation interaction statistics 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on Dykes, J. coordinated views exploratory data analysis Brunsdon, C. geographical weighting directional multivariate scale infovis07--4376136 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Visualizing the History of Living Spaces. The technology available to building designers now makes it possible to monitor buildings on a very large scale. Video cameras and motion sensors are commonplace in practically every office space, and are slowly making their way into living spaces. The application of such technologies, in particular video cameras, while improving security, also violates privacy. On the other hand, motion sensors, while being privacy-conscious, typically do not provide enough information for a human operator to maintain the same degree of awareness about the space that can be achieved by using video cameras. We propose a novel approach in which we use a large number of simple motion sensors and a small set of video cameras to monitor a large office space. In our system we deployed 215 motion sensors and six video cameras to monitor the 3,000-square-meter office space occupied by 80 people for a period of about one year. The main problem in operating such systems is finding a way to present this highly multidimensional data, which includes both spatial and temporal components, to a human operator to allow browsing and searching recorded data in an efficient and intuitive way. In this paper we present our experiences and the solutions that we have developed in the course of our work on the system. We consider this work to be the first step in helping designers and managers of building systems gain access to information about occupants' behavior in the context of an entire building in a way that is only minimally intrusive to the occupants' privacy. history awareness 2007 security surveillance user interface InfoVis Visualization and Computer Graphics, IEEE Transactions on timeline Ivanov, Y.A. Wren, C.R. Sorokin, A. Kaur, I. sensor networks spatio-temporal visualization infovis07--4376137 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Legible Cities: Focus-Dependent Multi-Resolution Visualization of Urban Relationships. Numerous systems have been developed to display large collections of data for urban contexts; however, most have focused on layering of single dimensions of data and manual calculations to understand relationships within the urban environment. Furthermore, these systems often limit the user's perspectives on the data, thereby diminishing the user's spatial understanding of the viewing region. In this paper, we introduce a highly interactive urban visualization tool that provides intuitive understanding of the urban data. Our system utilizes an aggregation method that combines buildings and city blocks into legible clusters, thus providing continuous levels of abstraction while preserving the user's mental model of the city. In conjunction with a 3D view of the urban model, a separate but integrated information visualization view displays multiple disparate dimensions of the urban data, allowing the user to understand the urban environment both spatially and cognitively in one glance. For our evaluation, expert users from various backgrounds viewed a real city model with census data and confirmed that our system allowed them to gain more intuitive and deeper understanding of the urban model from different perspectives and levels of abstraction than existing commercial urban visualization systems. Ribarsky, W. Chang, R. evaluation information visualization 2007 Kosara, R. InfoVis Visualization and Computer Graphics, IEEE Transactions on Wessel, G. Sauda, E. multi-resolution urban models infovis07--4376138 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Interactive Visual Exploration of a Large Spatio-temporal Dataset: Reflections on a Geovisualization Mashup.. Exploratory visual analysis is useful for the preliminary investigation of large structured, multifaceted spatio-temporal datasets. This process requires the selection and aggregation of records by time, space and attribute, the ability to transform data and the flexibility to apply appropriate visual encodings and interactions. We propose an approach inspired by geographical 'mashups' in which freely-available functionality and data are loosely but flexibly combined using de facto exchange standards. Our case study combines MySQL, PHP and the LandSerf GIS to allow Google Earth to be used for visual synthesis and interaction with encodings described in KML. This approach is applied to the exploration of a log of 1.42 million requests made of a mobile directory service. Novel combinations of interaction and visual encoding are developed including spatial 'tag clouds', 'tag maps', 'data dials' and multi-scale density surfaces. Four aspects of the approach are informally evaluated: the visual encodings employed, their success in the visual exploration of the dataset, the specific tools used and the 'mashup' approach. Preliminary findings will be beneficial to others considering using mashups for visualization. The specific techniques developed may be more widely applied to offer insights into the structure of multifarious spatio-temporal data of the type explored here. interaction case study 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on Dykes, J. Slingsby, A. Wood, J. geovisualization Clarke, K. large dataset visualization applications of infovis geographic visualization multiresolution visualization text and document visualization infovis07--4376139 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Hotmap: Looking at Geographic Attention. Understanding how people use online maps allows data acquisition teams to concentrate their efforts on the portions of the map that are most seen by users. Online maps represent vast databases, and so it is insufficient to simply look at a list of the most-accessed URLs. Hotmap takes advantage of the design of a mapping system's imagery pyramid to superpose a heatmap of the log files over the original maps. Users' behavior within the system can be observed and interpreted. This paper discusses the imagery acquisition task that motivated Hotmap, and presents several examples of information that Hotmap makes visible. We discuss the design choices behind Hotmap, including logarithmic color schemes; low-saturation background images; and tuning images to explore both infrequently-viewed and frequently-viewed spaces. Fisher, D. geographic 2007 InfoVis color Visualization and Computer Graphics, IEEE Transactions on GIS social navigation geographical visualization heatmap online mapping systems server log analysis infovis07--4376140 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on VisLink: Revealing Relationships Amongst Visualizations. We present VisLink, a method by which visualizations and the relationships between them can be interactively explored. VisLink readily generalizes to support multiple visualizations, empowers inter-representational queries, and enables the reuse of the spatial variables, thus supporting efficient information encoding and providing for powerful visualization bridging. Our approach uses multiple 2D layouts, drawing each one in its own plane. These planes can then be placed and re-positioned in 3D space: side by side, in parallel, or in chosen placements that provide favoured views. Relationships, connections, and patterns between visualizations can be revealed and explored using a variety of interaction techniques including spreading activation and search filters. interaction Collins, C. 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on Carpendale, S. graph visualization hierarchies 3D visualization node-link diagram edge aggregation structural comparison infovis07--4376141 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Visualization of Heterogeneous Data. Both the resource description framework (RDF), used in the semantic web, and Maya Viz u-forms represent data as a graph of objects connected by labeled edges. Existing systems for flexible visualization of this kind of data require manual specification of the possible visualization roles for each data attribute. When the schema is large and unfamiliar, this requirement inhibits exploratory visualization by requiring a costly up-front data integration step. To eliminate this step, we propose an automatic technique for mapping data attributes to visualization attributes. We formulate this as a schema matching problem, finding appropriate paths in the data model for each required visualization attribute in a visualization template. graph Hanrahan, P. 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on Talbot, J. Chan, B. Cammarano, M. Klingner, J. Dong, X. Halevy, A. data integration RDF attribute inference infovis07--4376142 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Sequential Document Visualization. Documents and other categorical valued time series are often characterized by the frequencies of short range sequential patterns such as n-grams. This representation converts sequential data of varying lengths to high dimensional histogram vectors which are easily modeled by standard statistical models. Unfortunately, the histogram representation ignores most of the medium and long range sequential dependencies making it unsuitable for visualizing sequential data. We present a novel framework for sequential visualization of discrete categorical time series based on the idea of local statistical modeling. The framework embeds categorical time series as smooth curves in the multinomial simplex summarizing the progression of sequential trends. We discuss several visualization techniques based on the above framework and demonstrate their usefulness for document visualization. document time series categorical 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on Lebanon, G. Mao, Y. Dillon, J.V. document visualization local fitting multi-resolution analysis infovis07--4376143 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on A Taxonomy of Clutter Reduction for Information Visualisation. Information visualisation is about gaining insight into data through a visual representation. This data is often multivariate and increasingly, the datasets are very large. To help us explore all this data, numerous visualisation applications, both commercial and research prototypes, have been designed using a variety of techniques and algorithms. Whether they are dedicated to geo-spatial data or skewed hierarchical data, most of the visualisations need to adopt strategies for dealing with overcrowded displays, brought about by too much data to fit in too small a display space. This paper analyses a large number of these clutter reduction methods, classifying them both in terms of how they deal with clutter reduction and more importantly, in terms of the benefits and losses. The aim of the resulting taxonomy is to act as a guide to match techniques to problems where different criteria may have different importance, and more importantly as a means to critique and hence develop existing and new techniques. insight taxonomy 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on taxonomy occlusion information visualization Ellis, G. Dix, A. clutter reduction large datasets infovis07--4376144 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Toward a Deeper Understanding of the Role of Interaction in Information Visualization. Even though interaction is an important part of information visualization (Infovis), it has garnered a relatively low level of attention from the Infovis community. A few frameworks and taxonomies of Infovis interaction techniques exist, but they typically focus on low-level operations and do not address the variety of benefits interaction provides. After conducting an extensive review of Infovis systems and their interactive capabilities, we propose seven general categories of interaction techniques widely used in Infovis: 1) Select, 2) Explore, 3) Reconfigure, 4) Encode, 5) Abstract/Elaborate, 6) Filter, and 7) Connect. These categories are organized around a user's intent while interacting with a system rather than the low-level interaction techniques provided by a system. The categories can act as a framework to help discuss and evaluate interaction techniques and hopefully lay an initial foundation toward a deeper understanding and a science of interaction. interaction visual analytics interaction Stasko, J. filter Kang, Y. 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization taxonomy interaction techniques Yi, J.S. Jacko, J.A. infovis07--4376145 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Interactive Tree Comparison for Co-located Collaborative Information Visualization. In many domains, increased collaboration has lead to more innovation by fostering the sharing of knowledge, skills, and ideas. Shared analysis of information visualizations does not only lead to increased information processing power, but team members can also share, negotiate, and discuss their views and interpretations on a dataset and contribute unique perspectives on a given problem. Designing technologies to support collaboration around information visualizations poses special challenges and relatively few systems have been designed. We focus on supporting small groups collaborating around information visualizations in a co-located setting, using a shared interactive tabletop display. We introduce an analysis of challenges and requirements for the design of co-located collaborative information visualization systems. We then present a new system that facilitates hierarchical data comparison tasks for this type of collaborative work. Our system supports multi-user input, shared and individual views on the hierarchical data visualization, flexible use of representations, and flexible workspace organization to facilitate group work around visualizations. collaboration Isenberg, P. collaboration 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on Carpendale, S. information visualization co-located work hierarchical data comparison infovis07--4376146 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Animated Transitions in Statistical Data Graphics. In this paper we investigate the effectiveness of animated transitions between common statistical data graphics such as bar charts, pie charts, and scatter plots. We extend theoretical models of data graphics to include such transitions, introducing a taxonomy of transition types. We then propose design principles for creating effective transitions and illustrate the application of these principles in DynaVis, a visualization system featuring animated data graphics. Two controlled experiments were conducted to assess the efficacy of various transition types, finding that animated transitions can significantly improve graphical perception. information visualization perception taxonomy Robertson, G. 2007 design Heer, J. animation InfoVis Visualization and Computer Graphics, IEEE Transactions on experiment statistical data graphics transitions infovis07--4376147 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Browsing Zoomable Treemaps: Structure-Aware Multi-Scale Navigation Techniques. Treemaps provide an interesting solution for representing hierarchical data. However, most studies have mainly focused on layout algorithms and paid limited attention to the interaction with treemaps. This makes it difficult to explore large data sets and to get access to details, especially to those related to the leaves of the trees. We propose the notion of zoomable treemaps (ZTMs), an hybridization between treemaps and zoomable user interfaces that facilitates the navigation in large hierarchical data sets. By providing a consistent set of interaction techniques, ZTMs make it possible for users to browse through very large data sets (e.g., 700,000 nodes dispatched amongst 13 levels). These techniques use the structure of the displayed data to guide the interaction and provide a way to improve interactive navigation in treemaps. interaction navigation 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization Blanch, R. Lecolinet, E. multi-scale interaction structure-aware navigation zoomable treemaps infovis07--4376148 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Visualizing Causal Semantics Using Animations. Michotte's theory of ampliation suggests that causal relationships are perceived by objects animated under appropriate spatiotemporal conditions. We extend the theory of ampliation and propose that the immediate perception of complex causal relations is also dependent on a set of structural and temporal rules. We designed animated representations, based on Michotte's rules, for showing complex causal relationships or causal semantics. In this paper we describe a set of animations for showing semantics such as causal amplification, causal strength, causal dampening, and causal multiplicity. In a two part study we compared the effectiveness of both the static and animated representations. The first study (N=44) asked participants to recall passages that were previously displayed using both types of representations. Participants were 8% more accurate in recalling causal semantics when they were presented using animations instead of static graphs. In the second study (N=112) we evaluated the intuitiveness of the representations. Our results showed that while users were as accurate with the static graphs as with the animations, they were 9% faster in matching the correct causal statements in the animated condition. Overall our results show that animated diagrams that are designed based on perceptual rules such as those proposed by Michotte have the potential to facilitate comprehension of complex causal relations. visualization theory perception 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on perception Irani, P.P. Kadaba, N.R. Leboe, J. causality animated graphs graph semantics semantics visualizing cause and effect infovis07--4376149 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Spatialization Design: Comparing Points and Landscapes. Spatializations represent non-spatial data using a spatial layout similar to a map. We present an experiment comparing different visual representations of spatialized data, to determine which representations are best for a non-trivial search and point estimation task. Primarily, we compare point-based displays to 2D and 3D information landscapes. We also compare a colour (hue) scale to a grey (lightness) scale. For the task we studied, point-based spatializations were far superior to landscapes, and 2D landscapes were superior to 3D landscapes. Little or no benefit was found for redundantly encoding data using colour or greyscale combined with landscape height. 3D landscapes with no colour scale (height-only) were particularly slow and inaccurate. A colour scale was found to be better than a greyscale for all display types, but a greyscale was helpful compared to height-only. These results suggest that point-based spatializations should be chosen over landscape representations, at least for tasks involving only point data itself rather than derived information about the data space. Tory, M. Munzner, T. experiment 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on Sprague, D.W. Fuqu Wu So, W.Y. 2D 3D colour greyscale information landscape numerosity points spatialization surface user study infovis07--4376150 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Weaving Versus Blending: a quantitative assessment of the information carrying capacities of two alternative methods for conveying multivariate data with color. In many applications, it is important to understand the individual values of, and relationships between, multiple related scalar variables defined across a common domain. Several approaches have been proposed for representing data in these situations. In this paper we focus on strategies for the visualization of multivariate data that rely on color mixing. In particular, through a series of controlled observer experiments, we seek to establish a fundamental understanding of the information-carrying capacities of two alternative methods for encoding multivariate information using color: color blending and color weaving. We begin with a baseline experiment in which we assess participants' abilities to accurately read numerical data encoded in six different basic color scales defined in the L*a*b* color space. We then assess participants' abilities to read combinations of 2, 3, 4 and 6 different data values represented in a common region of the domain, encoded using either color blending or color weaving. In color blending a single mixed color is formed via linear combination of the individual values in L*a*b* space, and in color weaving the original individual colors are displayed side-by-side in a high frequency texture that fills the region. A third experiment was conducted to clarify some of the trends regarding the color contrast and its effect on the magnitude of the error that was observed in the second experiment. The results indicate that when the component colors are represented side-by-side in a high frequency texture, most participants' abilities to infer the values of individual components are significantly improved, relative to when the colors are blended. Participants' performance was significantly better with color weaving particularly when more than 2 colors were used, and even when the individual colors subtended only 3 minutes of visual angle in the texture. However, the information-carrying capacity of the color weaving approach has its limits. - - We found that participants' abilities to accurately interpret each of the individual components in a high frequency color texture typically falls off as the number of components increases from 4 to 6. We found no significant advantages, in either color blending or color weaving, to using color scales based on component hues thatare more widely separated in the L*a*b* color space. Furthermore, we found some indications that extra difficulties may arise when opponent hues are employed. visualization experiment 2007 Kim, S. InfoVis color Visualization and Computer Graphics, IEEE Transactions on Hagh-Shenas, H. Interrante, V. perception Healey, C. color color blending color weaving infovis07--4376151 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Overview Use in Multiple Visual Information Resolution Interfaces. In interfaces that provide multiple visual information resolutions (VIR), low-VIR overviews typically sacrifice visual details for display capacity, with the assumption that users can select regions of interest to examine at higher VI Rs. Designers can create low VIRs based on multi-level structure inherent in the data, but have little guidance with single-level data. To better guide design tradeoff between display capacity and visual target perceivability, we looked at overview use in two multiple-VIR interfaces with high-VIR displays either embedded within, or separate from, the overviews. We studied two visual requirements for effective overview and found that participants would reliably use the low-VIR overviews only when the visual targets were simple and had small visual spans. Otherwise, at least 20% chose to use the high-VIR view exclusively. Surprisingly, neither of the multiple-VIR interfaces provided performance benefits when compared to using the high-VIR view alone. However, we did observe benefits in providing side-by-side comparisons for target matching. We conjecture that the high cognitive load of multiple-VIR interface interactions, whether real or perceived, is a more considerable barrier to their effective use than was previously considered. overview Munzner, T. Kincaid, R. 2007 Lam, H. InfoVis Visualization and Computer Graphics, IEEE Transactions on user study multiple resolutions overview use infovis07--4376152 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Visualizing Changes of Hierarchical Data using Treemaps. While the treemap is a popular method for visualizing hierarchical data, it is often difficult for users to track layout and attribute changes when the data evolve over time. When viewing the treemaps side by side or back and forth, there exist several problems that can prevent viewers from performing effective comparisons. Those problems include abrupt layout changes, a lack of prominent visual patterns to represent layouts, and a lack of direct contrast to highlight differences. In this paper, we present strategies to visualize changes of hierarchical data using treemaps. A new treemap layout algorithm is presented to reduce abrupt layout changes and produce consistent visual patterns. Techniques are proposed to effectively visualize the difference and contrast between two treemap snapshots in terms of the map items' colors, sizes, and positions. Experimental data show that our algorithm can achieve a good balance in maintaining a treemap's stability, continuity, readability, and average aspect ratio. A software tool is created to compare treemaps and generate the visualizations. User studies show that the users can better understand the changes in the hierarchy and layout, and more quickly notice the color and size differences using our method. Shen, H.-W. 2007 hierarchy InfoVis color Visualization and Computer Graphics, IEEE Transactions on treemap treemap Tu, Y. tree comparison treemap layout algorithm visualize changes infovis07--4376153 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Exploring Multiple Trees through DAG Representations. We present a directed acyclic graph visualisation designed to allow interaction with a set of multiple classification trees, specifically to find overlaps and differences between groups of trees and individual trees. The work is motivated by the need to find a representation for multiple trees that has the space-saving property of a general graph representation and the intuitive parent-child direction cues present in individual representation of trees. Using example taxonomic data sets, we describe augmentations to the common barycenter DAG layout method that reveal shared sets of child nodes between common parents in a clearer manner. Other interactions such as displaying the multiple ancestor paths of a node when it occurs in several trees, and revealing intersecting sibling sets within the context of a single DAG representation are also discussed. interaction graph 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on Kennedy, J. Graham, M. directed acyclic graph multiple trees infovis07--4376154 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on NodeTrix: a Hybrid Visualization of Social Networks. The need to visualize large social networks is growing as hardware capabilities make analyzing large networks feasible and many new data sets become available. Unfortunately, the visualizations in existing systems do not satisfactorily resolve the basic dilemma of being readable both for the global structure of the network and also for detailed analysis of local communities. To address this problem, we present NodeTrix, a hybrid representation for networks that combines the advantages of two traditional representations: node-link diagrams are used to show the global structure of a network, while arbitrary portions of the network can be shown as adjacency matrices to better support the analysis of communities. A key contribution is a set of interaction techniques. These allow analysts to create a NodeTrix visualization by dragging selections to and from node-link and matrix forms, and to flexibly manipulate the NodeTrix representation to explore the dataset and create meaningful summary visualizations of their findings. Finally, we present a case study applying NodeTrix to the analysis of the InfoVis 2004 coauthorship dataset to illustrate the capabilities of NodeTrix as both an exploration tool and an effective means of communicating results. interaction interaction social Fekete, J.-D. network case study matrix hardware 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on McGuffin, M.J. Henry Riche, N. network visualization aggregation hybrid visualization matrix visualization infovis07--4376155 10/28/2007 Visualization and Computer Graphics, IEEE Transactions on Multi-Level Graph Layout on the GPU. This paper presents a new algorithm for force directed graph layout on the GPU. The algorithm, whose goal is to compute layouts accurately and quickly, has two contributions. The first contribution is proposing a general multi-level scheme, which is based on spectral partitioning. The second contribution is computing the layout on the GPU. Since the GPU requires a data parallel programming model, the challenge is devising a mapping of a naturally unstructured graph into a well-partitioned structured one. This is done by computing a balanced partitioning of a general graph. This algorithm provides a general multi-level scheme, which has the potential to be used not only for computation on the GPU, but also on emerging multi-core architectures. The algorithm manages to compute high quality layouts of large graphs in a fraction of the time required by existing algorithms of similar quality. An application for visualization of the topologies of ISP (Internet service provider) networks is presented. graph graph layout 2007 InfoVis Visualization and Computer Graphics, IEEE Transactions on graph layout graph partitioning Tal, A. Frishman, Y. GPU infovis08--4658123 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Rolling the Dice: Multidimensional Visual Exploration using Scatterplot Matrix Navigation. Scatterplots remain one of the most popular and widely-used visual representations for multidimensional data due to their simplicity, familiarity and visual clarity, even if they lack some of the flexibility and visual expressiveness of newer multidimensional visualization techniques. This paper presents new interactive methods to explore multidimensional data using scatterplots. This exploration is performed using a matrix of scatterplots that gives an overview of the possible configurations, thumbnails of the scatterplots, and support for interactive navigation in the multidimensional space. Transitions between scatterplots are performed as animated rotations in 3D space, somewhat akin to rolling dice. Users can iteratively build queries using bounding volumes in the dataset, sculpting the query from different viewpoints to become more and more refined. Furthermore, the dimensions in the navigation space can be reordered, manually or automatically, to highlight salient correlations and differences among them. An example scenario presents the interaction techniques supporting smooth and effortless visual exploration of multidimensional datasets. interaction visual analytics Fekete, J.-D. scatterplot visual exploration overview multivariate data interaction matrix navigation 2008 Elmqvist, N. InfoVis Visualization and Computer Graphics, IEEE Transactions on Dragicevic, P. navigation visual queries infovis08--4658124 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on A Framework of Interaction Costs in Information Visualization. Interaction cost is an important but poorly understood factor in visualization design. We propose a framework of interaction costs inspired by Normanpsilas Seven Stages of Action to facilitate study. From 484 papers, we collected 61 interaction-related usability problems reported in 32 user studies and placed them into our framework of seven costs: (1) Decision costs to form goals; (2) system-power costs to form system operations; (3) Multiple input mode costs to form physical sequences; (4) Physical-motion costs to execute sequences; (5) Visual-cluttering costs to perceive state; (6) View-change costs to interpret perception; (7) State-change costs to evaluate interpretation. We also suggested ways to narrow the gulfs of execution (2-4) and evaluation (5-7) based on collected reports. Our framework suggests a need to consider decision costs (1) as the gulf of goal formation. interaction interaction information visualization evaluation usability perception 2008 Lam, H. InfoVis Visualization and Computer Graphics, IEEE Transactions on framework interface evaluation infovis08--4658125 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Balloon Focus: a Seamless Multi-Focus+Context Method for Treemaps. The treemap is one of the most popular methods for visualizing hierarchical data. When a treemap contains a large number of items, inspecting or comparing a few selected items in a greater level of detail becomes very challenging. In this paper, we present a seamless multi-focus and context technique, called Balloon Focus, that allows the user to smoothly enlarge multiple treemap items served as the foci, while maintaining a stable treemap layout as the context. Our method has several desirable features. First, this method is quite general and can be used with different treemap layout algorithms. Second, as the foci are enlarged, the relative positions among all items are preserved. Third, the foci are placed in a way that the remaining space is evenly distributed back to the non-focus treemap items. When Balloon Focus enlarges the focus items to a maximum degree, the above features ensure that the treemap will maintain a consistent appearance and avoid any abrupt layout changes. In our algorithm, a DAG (Directed Acyclic Graph) is used to maintain the positional constraints, and an elastic model is employed to govern the placement of the treemap items. We demonstrate a treemap visualization system that integrates data query, manual focus selection, and our novel multi-focus+context technique, Balloon Focus, together. A user study was conducted. Results show that with Balloon Focus, users can better perform the tasks of comparing the values and the distribution of the foci. user study graph Shen, H.-W. 2008 InfoVis Visualization and Computer Graphics, IEEE Transactions on treemap focus+context focus+context treemap fisheye Tu, Y. magnification multi-focus multi-scale viewing visualizing query results infovis08--4658126 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Multi-Focused Geospatial Analysis Using Probes. Traditional geospatial information visualizations often present views that restrict the user to a single perspective. When zoomed out, local trends and anomalies become suppressed and lost; when zoomed in for local inspection, spatial awareness and comparison between regions become limited. In our model, coordinated visualizations are integrated within individual probe interfaces, which depict the local data in user-defined regions-of-interest. Our probe concept can be incorporated into a variety of geospatial visualizations to empower users with the ability to observe, coordinate, and compare data across multiple local regions. It is especially useful when dealing with complex simulations or analyses where behavior in various localities differs from other localities and from the system as a whole. We illustrate the effectiveness of our technique over traditional interfaces by incorporating it within three existing geospatial visualization systems: an agent-based social simulation, a census data exploration tool, and an 3D GIS environment for analyzing urban change over time. In each case, the probe-based interaction enhances spatial awareness, improves inspection and comparison capabilities, expands the range of scopes, and facilitates collaboration among multiple users. interaction Ribarsky, W. Chang, R. Dou, W. collaboration social geospatial 2008 awareness InfoVis Visualization and Computer Graphics, IEEE Transactions on Butkiewicz, T. Wartell, Z. multiple-view techniques focus+context geospatial analysis geospatial visualization probes infovis08--4658127 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Distributed Cognition as a Theoretical Framework for Information Visualization. Even though information visualization (InfoVis) research has matured in recent years, it is generally acknowledged that the field still lacks supporting, encompassing theories. In this paper, we argue that the distributed cognition framework can be used to substantiate the theoretical foundation of InfoVis. We highlight fundamental assumptions and theoretical constructs of the distributed cognition approach, based on the cognitive science literature and a real life scenario. We then discuss how the distributed cognition framework can have an impact on the research directions and methodologies we take as InfoVis researchers. Our contributions are as follows. First, we highlight the view that cognition is more an emergent property of interaction than a property of the human mind. Second, we argue that a reductionist approach to study the abstract properties of isolated human minds may not be useful in informing InfoVis design. Finally we propose to make cognition an explicit research agenda, and discuss the implications on how we perform evaluation and theory building. interaction Liu, Z. evaluation interaction Stasko, J. theory 2008 cognition InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization distributed cognition Nersessian, N. representation theory and methods infovis08--4658128 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on EMDialog: Bringing Information Visualization into the Museum. Digital information displays are becoming more common in public spaces such as museums, galleries, and libraries. However, the public nature of these locations requires special considerations concerning the design of information visualization in terms of visual representations and interaction techniques. We discuss the potential for, and challenges of, information visualization in the museum context based on our practical experience with EMDialog, an interactive information presentation that was part of the Emily Carr exhibition at the Glenbow Museum in Calgary. EMDialog visualizes the diverse and multi-faceted discourse about this Canadian artist with the goal to both inform and provoke discussion. It provides a visual exploration environment that offers interplay between two integrated visualizations, one for information access along temporal, and the other along contextual dimensions. We describe the results of an observational study we conducted at the museum that revealed the different ways visitors approached and interacted with EMDialog, as well as how they perceived this form of information presentation in the museum context. Our results include the need to present information in a manner sufficiently attractive to draw attention and the importance of rewarding passive observation as well as both short- and longer term information exploration. interaction 2008 InfoVis Visualization and Computer Graphics, IEEE Transactions on Carpendale, S. Hinrichs, U. Schmidt, H. artistic information visualization interactive information visualization public displays walk-up-and-use interaction infovis08--4658129 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Graphical Histories for Visualization: Supporting Analysis, Communication, and Evaluation. Interactive history tools, ranging from basic undo and redo to branching timelines of user actions, facilitate iterative forms of interaction. In this paper, we investigate the design of history mechanisms for information visualization. We present a design space analysis of both architectural and interface issues, identifying design decisions and associated trade-offs. Based on this analysis, we contribute a design study of graphical history tools for Tableau, a database visualization system. These tools record and visualize interaction histories, support data analysis and communication of findings, and contribute novel mechanisms for presenting, managing, and exporting histories. Furthermore, we have analyzed aggregated collections of history sessions to evaluate Tableau usage. We describe additional tools for analyzing userspsila history logs and how they have been applied to study usage patterns in Tableau. interaction history evaluation evaluation history visualization 2008 database Heer, J. Agrawala, M. analysis InfoVis Visualization and Computer Graphics, IEEE Transactions on design study Mackinlay, J.D. Stolte, C. presentation undo infovis08--4658130 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Who Votes For What? A Visual Query Language for Opinion Data. Surveys and opinion polls are extremely popular in the media, especially in the months preceding a general election. However, the available tools for analyzing poll results often require specialized training. Hence, data analysis remains out of reach for many casual computer users. Moreover, the visualizations used to communicate the results of surveys are typically limited to traditional statistical graphics like bar graphs and pie charts, both of which are fundamentally noninteractive. We present a simple interactive visualization that allows users to construct queries on large tabular data sets, and view the results in real time. The results of two separate user studies suggest that our interface lowers the learning curve for naive users, while still providing enough analytical power to discover interesting correlations in the data. 2008 InfoVis Visualization and Computer Graphics, IEEE Transactions on radial visualization human-computer interaction Draper, G. Riesenfeld, R. visual query languages data analysis infovis08--4658131 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on VisGets: Coordinated Visualizations for Web-based Information Exploration and Discovery. In common Web-based search interfaces, it can be difficult to formulate queries that simultaneously combine temporal, spatial, and topical data filters. We investigate how coordinated visualizations can enhance search and exploration of information on the World Wide Web by easing the formulation of these types of queries. Drawing from visual information seeking and exploratory search, we introduce VisGets - interactive query visualizations of Web-based information that operate with online information within a Web browser. VisGets provide the information seeker with visual overviews of Web resources and offer a way to visually filter the data. Our goal is to facilitate the construction of dynamic search queries that combine filters from more than one data dimension. We present a prototype information exploration system featuring three linked VisGets (temporal, spatial, and topical), and used it to visually explore news items from online RSS feeds. information retrieval Collins, C. filter 2008 InfoVis Visualization and Computer Graphics, IEEE Transactions on Carpendale, S. World Wide Web Williamson, C. information visualization world wide web Dork, M. exploratory search visual information seeking infovis08--4658132 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Vispedia: Interactive Visual Exploration of Wikipedia Data via Search-Based Integration. Wikipedia is an example of the collaborative, semi-structured data sets emerging on the Web. These data sets have large, non-uniform schema that require costly data integration into structured tables before visualization can begin. We present Vispedia, a Web-based visualization system that reduces the cost of this data integration. Users can browse Wikipedia, select an interesting data table, then use a search interface to discover, integrate, and visualize additional columns of data drawn from multiple Wikipedia articles. This interaction is supported by a fast path search algorithm over DBpedia, a semantic graph extracted from Wikipedia's hyperlink structure. Vispedia can also export the augmented data tables produced for use in traditional visualization systems. We believe that these techniques begin to address the "long tail" of visualization by allowing a wider audience to visualize a broader class of data. We evaluated this system in a first-use formative lab study. Study participants were able to quickly create effective visualizations for a diverse set of domains, performing data integration as needed. interaction graph information visualization 2008 Hanrahan, P. Wikipedia InfoVis Visualization and Computer Graphics, IEEE Transactions on Talbot, J. Chan, B. Cammarano, M. Wu, L. data integration search interface semantic web infovis08--4658133 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on The Word Tree, an Interactive Visual Concordance. We introduce the Word Tree, a new visualization and information-retrieval technique aimed at text documents. A Word Tree is a graphical version of the traditional "keyword-in-context" method, and enables rapid querying and exploration of bodies of text. In this paper we describe the design of the technique, along with some of the technical issues that arise in its implementation. In addition, we discuss the results of several months of public deployment of word trees on Many Eyes, which provides a window onto the ways in which users obtain value from the visualization. text information retrieval Wattenberg, M. Viegas, F.B. text visualization 2008 InfoVis Visualization and Computer Graphics, IEEE Transactions on case study document visualization Many Eyes concordance search infovis08--4658134 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on HiPP: A Novel Hierarchical Point Placement Strategy and its Application to the Exploration of Document Collections. Point placement strategies aim at mapping data points represented in higher dimensions to bi-dimensional spaces and are frequently used to visualize relationships amongst data instances. They have been valuable tools for analysis and exploration of data sets of various kinds. Many conventional techniques, however, do not behave well when the number of dimensions is high, such as in the case of documents collections. Later approaches handle that shortcoming, but may cause too much clutter to allow flexible exploration to take place. In this work we present a novel hierarchical point placement technique that is capable of dealing with these problems. While good grouping and separation of data with high similarity is maintained without increasing computation cost, its hierarchical structure lends itself both to exploration in various levels of detail and to handling data in subsets, improving analysis capability and also allowing manipulation of larger data sets. document 2008 Paulovich, F.V. Minghim, R. InfoVis Visualization and Computer Graphics, IEEE Transactions on text and document visualization hierarchical multidimensional visualization high-dimensional data visual knowledge discovery infovis08--4658135 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Particle-based labeling: Fast point-feature labeling without obscuring other visual features. In many information visualization techniques, labels are an essential part to communicate the visualized data. To preserve the expressiveness of the visual representation, a placed label should neither occlude other labels nor visual representatives (e.g., icons, lines) that communicate crucial information. Optimal, non-overlapping labeling is an NP-hard problem. Thus, only a few approaches achieve a fast non-overlapping labeling in highly interactive scenarios like information visualization. These approaches generally target the point-feature label placement (PFLP) problem, solving only label-label conflicts. This paper presents a new, fast, solid and flexible 2D labeling approach for the PFLP problem that additionally respects other visual elements and the visual extent of labeled features. The results (number of placed labels, processing time) of our particle-based method compare favorably to those of existing techniques. Although the esthetic quality of non-real-time approaches may not be achieved with our method, it complies with practical demands and thus supports the interactive exploration of information spaces. In contrast to the known adjacent techniques, the flexibility of our technique enables labeling of dense point clouds by the use of non-occluding distant labels. Our approach is independent of the underlying visualization technique, which enables us to demonstrate the application of our labeling method within different information visualization scenarios. information visualization 2008 InfoVis Visualization and Computer Graphics, IEEE Transactions on Schumann, H. Luboschik, M. Cords, H. automatic label placement dynamic labeling interactive labeling occlusion-free infovis08--4658136 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Stacked Graphs ? Geometry & Aesthetics. In February 2008, the New York Times published an unusual chart of box office revenues for 7500 movies over 21 years. The chart was based on a similar visualization, developed by the first author, that displayed trends in music listening. This paper describes the design decisions and algorithms behind these graphics, and discusses the reaction on the Web. We suggest that this type of complex layered graph is effective for displaying large data sets to a mass audience. We provide a mathematical analysis of how this layered graph relates to traditional stacked graphs and to techniques such as ThemeRiver, showing how each method is optimizing a different ldquoenergy functionrdquo. Finally, we discuss techniques for coloring and ordering the layers of such graphs. Throughout the paper, we emphasize the interplay between considerations of aesthetics and legibility. graph Wattenberg, M. 2008 InfoVis Visualization and Computer Graphics, IEEE Transactions on listening history aesthetics Byron, L. streamgraph ThemeRiver aesthetics communication-minded visualization last.fm time series infovis08--4658137 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Cerebral: Visualizing Multiple Experimental Conditions on a Graph with Biological Context. Systems biologists use interaction graphs to model the behavior of biological systems at the molecular level. In an iterative process, such biologists observe the reactions of living cells under various experimental conditions, view the results in the context of the interaction graph, and then propose changes to the graph model. These graphs serve as a form of dynamic knowledge representation of the biological system being studied and evolve as new insight is gained from the experimental data. While numerous graph layout and drawing packages are available, these tools did not fully meet the needs of our immunologist collaborators. In this paper, we describe the data information display needs of these immunologists and translate them into design decisions. These decisions led us to create Cerebral, a system that uses a biologically guided graph layout and incorporates experimental data directly into the graph display. Small multiple views of different experimental conditions and a data-driven parallel coordinates view enable correlations between experimental conditions to be analyzed at the same time that the data is viewed in the graph context. This combination of coordinated views allows the biologist to view the data from many different perspectives simultaneously. To illustrate the typical analysis tasks performed, we analyze two datasets using Cerebral. Based on feedback from our collaborators we conclude that Cerebral is a valuable tool for analyzing experimental data in the context of an interaction graph model. interaction insight graph graph layout coordinated views parallel coordinates Munzner, T. multiple views Kincaid, R. 2008 small multiples InfoVis Visualization and Computer Graphics, IEEE Transactions on design study graph layout Barsky, A. Gardy, J. systems biology visualization infovis08--4658138 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on The Shaping of Information by Visual Metaphors. The nature of an information visualization can be considered to lie in the visual metaphors it uses to structure information. The process of understanding a visualization therefore involves an interaction between these external visual metaphors and the user's internal knowledge representations. To investigate this claim, we conducted an experiment to test the effects of visual metaphor and verbal metaphor on the understanding of tree visualizations. Participants answered simple data comprehension questions while viewing either a treemap or a node-link diagram. Questions were worded to reflect a verbal metaphor that was either compatible or incompatible with the visualization a participant was using. The results suggest that the visual metaphor indeed affects how a user derives information from a visualization. Additionally, we found that the degree to which a user is affected by the metaphor is strongly correlated with the user's ability to answer task questions correctly. These findings are a first step towards illuminating how visual metaphors shape user understanding, and have significant implications for the evaluation, application, and theory of visualization. interaction Ziemkiewicz, C. evaluation evaluation theory 2008 experiment Kosara, R. InfoVis Visualization and Computer Graphics, IEEE Transactions on treemap hierarchies cognition metaphors visualization theory infovis08--4658139 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Viz-A-Vis: Toward Visualizing Video through Computer Vision. In the established procedural model of information visualization, the first operation is to transform raw data into data tables. The transforms typically include abstractions that aggregate and segment relevant data and are usually defined by a human, user or programmer. The theme of this paper is that for video, data transforms should be supported by low level computer vision. High level reasoning still resides in the human analyst, while part of the low level perception is handled by the computer. To illustrate this approach, we present Viz-A-Vis, an overhead video capture and access system for activity analysis in natural settings over variable periods of time. Overhead video provides rich opportunities for long-term behavioral and occupancy analysis, but it poses considerable challenges. We present initial steps addressing two challenges. First, overhead video generates overwhelmingly large volumes of video impractical to analyze manually. Second, automatic video analysis remains an open problem for computer vision. Stasko, J. Abowd, G.D. perception 2008 InfoVis Visualization and Computer Graphics, IEEE Transactions on time series data Romero, M. Summet, J. spatiotemporal visualization image/video analytics sensor analytics video visualization infovis08--4658140 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Geometry-Based Edge Clustering for Graph Visualization. Graphs have been widely used to model relationships among data. For large graphs, excessive edge crossings make the display visually cluttered and thus difficult to explore. In this paper, we propose a novel geometry-based edge-clustering framework that can group edges into bundles to reduce the overall edge crossings. Our method uses a control mesh to guide the edge-clustering process; edge bundles can be formed by forcing all edges to pass through some control points on the mesh. The control mesh can be generated at different levels of detail either manually or automatically based on underlying graph patterns. Users can further interact with the edge-clustering results through several advanced visualization techniques such as color and opacity enhancement. Compared with other edge-clustering methods, our approach is intuitive, flexible, and efficient. The experiments on some large graphs demonstrate the effectiveness of our method. graph clustering Wong, P.C. 2008 InfoVis color Visualization and Computer Graphics, IEEE Transactions on Qu, H. Zhou, H. Cui, W. graph visualization Li, X. edge clustering mesh visual clutter infovis08--4658141 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on On the Visualization of Social and other Scale-Free Networks. This paper proposes novel methods for visualizing specifically the large power-law graphs that arise in sociology and the sciences. In such cases a large portion of edges can be shown to be less important and removed while preserving component connectedness and other features (e.g. cliques) to more clearly reveal the networkpsilas underlying connection pathways. This simplification approach deterministically filters (instead of clustering) the graph to retain important node and edge semantics, and works both automatically and interactively. The improved graph filtering and layout is combined with a novel computer graphics anisotropic shading of the dense crisscrossing array of edges to yield a full social network and scale-free graph visualization system. Both quantitative analysis and visual results demonstrate the effectiveness of this approach. social network graph clustering 2008 InfoVis Visualization and Computer Graphics, IEEE Transactions on Garland, M. Jia, Y. Hoberock, J. Hart, J. scale-free network anisotropic shading betweenness centrality edge filtering infovis08--4658142 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Exploration of Networks using overview+detail with Constraint-based cooperative layout. A standard approach to large network visualization is to provide an overview of the network and a detailed view of a small component of the graph centred around a focal node. The user explores the network by changing the focal node in the detailed view or by changing the level of detail of a node or cluster. For scalability, fast force-based layout algorithms are used for the overview and the detailed view. However, using the same layout algorithm in both views is problematic since layout for the detailed view has different requirements to that in the overview. Here we present a model in which constrained graph layout algorithms are used for layout in the detailed view. This means the detailed view has high-quality layout including sophisticated edge routing and is customisable by the user who can add placement constraints on the layout. Scalability is still ensured since the slower layout techniques are only applied to the small subgraph shown in the detailed view. The main technical innovations are techniques to ensure that the overview and detailed view remain synchronized, and modifying constrained graph layout algorithms to support smooth, stable layout. The key innovation supporting stability are new dynamic graph layout algorithms that preserve the topology or structure of the network when the user changes the focus node or the level of detail by in situ semantic zooming. We have built a prototype tool and demonstrate its use in two application domains, UML class diagrams and biological networks. zooming network graph graph layout cluster overview 2008 InfoVis Visualization and Computer Graphics, IEEE Transactions on Dwyer, T. graph drawing multidimensional scaling Marriott, K. constraints force-directed algorithms stress majorization Schreiber, F. Stuckey, P. Woodward, M. Wybrow, M. infovis08--4658143 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Rapid Graph Layout Using Space Filling Curves. Network data frequently arises in a wide variety of fields, and node-link diagrams are a very natural and intuitive representation of such data. In order for a node-link diagram to be effective, the nodes must be arranged well on the screen. While many graph layout algorithms exist for this purpose, they often have limitations such as high computational complexity or node colocation. This paper proposes a new approach to graph layout through the use of space filling curves which is very fast and guarantees that there will be no nodes that are colocated. The resulting layout is also aesthetic and satisfies several criteria for graph layout effectiveness. network graph graph layout Ma, K.-L. Muelder, C. 2008 InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization graph layout space filling curves infovis08--4658144 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Evaluating the Use of Data Transformation for Information Visualization. Data transformation, the process of preparing raw data for effective visualization, is one of the key challenges in information visualization. Although researchers have developed many data transformation techniques, there is little empirical study of the general impact of data transformation on visualization. Without such study, it is difficult to systematically decide when and which data transformation techniques are needed. We thus have designed and conducted a two-part empirical study that examines how the use of common data transformation techniques impacts visualization quality, which in turn affects user task performance. Our first experiment studies the impact of data transformation on user performance in single-step, typical visual analytic tasks. The second experiment assesses the impact of data transformation in multi-step analytic tasks. Our results quantify the benefits of data transformation in both experiments. More importantly, our analyses reveal that (1) the benefits of data transformation vary significantly by task and by visualization, and (2) the use of data transformation depends on a user's interaction context. Based on our findings, we present a set of design recommendations that help guide the development and use of data transformation techniques. interaction Zhou, M.X. 2008 experiment InfoVis Visualization and Computer Graphics, IEEE Transactions on user study empirical evaluation Wen, Z. data cleaning data transformations infovis08--4658145 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Improving the Readability of Clustered Social Networks using Node Duplication. Exploring communities is an important task in social network analysis. Such communities are currently identified using clustering methods to group actors. This approach often leads to actors belonging to one and only one cluster, whereas in real life a person can belong to several communities. As a solution we propose duplicating actors in social networks and discuss potential impact of such a move. Several visual duplication designs are discussed and a controlled experiment comparing network visualization with and without duplication is performed, using 6 tasks that are important for graph readability and visual interpretation of social networks. We show that in our experiment, duplications significantly improve community-related tasks but sometimes interfere with other graph readability tasks. Finally, we propose a set of guidelines for deciding when to duplicate actors and choosing candidates for duplication, and alternative ways to render them in social network representations. social Fekete, J.-D. network graph cluster clustering 2008 experiment InfoVis Visualization and Computer Graphics, IEEE Transactions on Bezerianos, A. graph visualization clustering Henry Riche, N. node duplications social networks infovis08--4658146 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Effectiveness of Animation in Trend Visualization. Animation has been used to show trends in multi-dimensional data. This technique has recently gained new prominence for presentations, most notably with Gapminder Trendalyzer. In Trendalyzer, animation together with interesting data and an engaging presenter helps the audience understand the results of an analysis of the data. It is less clear whether trend animation is effective for analysis. This paper proposes two alternative trend visualizations that use static depictions of trends: one which shows traces of all trends overlaid simultaneously in one display and a second that uses a small multiples display to show the trend traces side-by-side. The paper evaluates the three visualizations for both analysis and presentation. Results indicate that trend animation can be challenging to use even for presentations; while it is the fastest technique for presentation and participants find it enjoyable and exciting, it does lead to many participant errors. Animation is the least effective form for analysis; both static depictions of trends are significantly faster than animation, and the small multiples display is more accurate. Fisher, D. Lee, B. Stasko, J. 2008 Robertson, G. design animation animation InfoVis Visualization and Computer Graphics, IEEE Transactions on Fernandez, R. information visualization small multiples experiment trends infovis08--4658147 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Perceptual Organization in User-Generated Graph Layouts. Many graph layout algorithms optimize visual characteristics to achieve useful representations. Implicitly, their goal is to create visual representations that are more intuitive to human observers. In this paper, we asked users to explicitly manipulate nodes in a network diagram to create layouts that they felt best captured the relationships in the data. This allowed us to measure organizational behavior directly, allowing us to evaluate the perceptual importance of particular visual features, such as edge crossings and edge-lengths uniformity. We also manipulated the interior structure of the node relationships by designing data sets that contained clusters, that is, sets of nodes that are strongly interconnected. By varying the degree to which these clusters were ldquomaskedrdquo by extraneous edges we were able to measure observerspsila sensitivity to the existence of clusters and how they revealed them in the network diagram. Based on these measurements we found that observers are able to recover cluster structure, that the distance between clusters is inversely related to the strength of the clustering, and that users exhibit the tendency to use edges to visually delineate perceptual groups. These results demonstrate the role of perceptual organization in representing graph data and provide concrete recommendations for graph layout algorithms. network graph graph layout cluster clustering 2008 InfoVis Visualization and Computer Graphics, IEEE Transactions on van Ham, F. user study graph layout Rogowitz, B. network layout visualization perceptual organization infovis08--4658148 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Interactive Visual Analysis of Set-Typed Data. While it is quite typical to deal with attributes of different data types in the visualization of heterogeneous and multivariate datasets, most existing techniques still focus on the most usual data types such as numerical attributes or strings. In this paper we present a new approach to the interactive visual exploration and analysis of data that contains attributes which are of set type. A set-typed attribute of a data item - like one cell in a table - has a list of nGt=0 elements as its value. We present the setpsilaopsilagram as a new visualization approach to represent data of set type and to enable interactive visual exploration and analysis. We also demonstrate how this approach is capable to help in dealing with datasets that have a larger number of dimensions (more than a dozen or more), especially also in the context of categorical data. To illustrate the effectiveness of our approach, we present the interactive visual analysis of a CRM dataset with data from a questionnaire on the education and shopping habits of about 90000 people. categorical education 2008 InfoVis Visualization and Computer Graphics, IEEE Transactions on Hauser, H. Matkovic, K. Freiler, W. focus+context visualization interactive visual analysis interactive visualization multidimensional multivariate data visualization multiple coordinated views infovis08--4658149 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Spatially Ordered Treemaps. Existing treemap layout algorithms suffer to some extent from poor or inconsistent mappings between data order and visual ordering in their representation, reducing their cognitive plausibility. While attempts have been made to quantify this mismatch, and algorithms proposed to minimize inconsistency, solutions provided tend to concentrate on one-dimensional ordering. We propose extensions to the existing squarified layout algorithm that exploit the two-dimensional arrangement of treemap nodes more effectively. Our proposed spatial squarified layout algorithm provides a more consistent arrangement of nodes while maintaining low aspect ratios. It is suitable for the arrangement of data with a geographic component and can be used to create tessellated cartograms for geovisualization. Locational consistency is measured and visualized and a number of layout algorithms are compared. CIELab color space and displacement vector overlays are used to assess and emphasize the spatial layout of treemap nodes. A case study involving locations of tagged photographs in the Flickr database is described. geographic case study 2008 database geovisualization InfoVis color Visualization and Computer Graphics, IEEE Transactions on treemap treemap Dykes, J. Wood, J. geovisualization CIELab cartogram geographic information tree structures infovis08--4658150 10/19/2008 Visualization and Computer Graphics, IEEE Transactions on Visualizing Incomplete and Partially Ranked Data. Ranking data, which result from m raters ranking n items, are difficult to visualize due to their discrete algebraic structure, and the computational difficulties associated with them when n is large. This problem becomes worse when raters provide tied rankings or not all items are ranked. We develop an approach for the visualization of ranking data for large n which is intuitive, easy to use, and computationally efficient. The approach overcomes the structural and computational difficulties by utilizing a natural measure of dissimilarity for raters, and projecting the raters into a low dimensional vector space where they are viewed. The visualization techniques are demonstrated using voting data, jokes, and movie preferences. 2008 Cleveland, W.S. InfoVis Visualization and Computer Graphics, IEEE Transactions on multidimensional scaling Lebanon, G. Kidwell, P. partial rankings incomplete rankings infovis09--5290726 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Mapping Text with Phrase Nets. We present a new technique, the phrase net, for generating visual overviews of unstructured text. A phrase net displays a graph whose nodes are words and whose edges indicate that two words are linked by a user-specified relation. These relations may be defined either at the syntactic or lexical level; different relations often produce very different perspectives on the same text. Taken together, these perspectives often provide an illuminating visual overview of the key concepts and relations in a document or set of documents. document text graph overview data visualisation 2009 text analysis Wattenberg, M. Viegas, F.B. text visualization InfoVis Visualization and Computer Graphics, IEEE Transactions on van Ham, F. tag cloud phrase nets text mapping user-specified relation visual overviews natural language processing semantic net infovis09--5290725 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Exemplar-based Visualization of Large Document Corpus. With the rapid growth of the World Wide Web and electronic information services, text corpus is becoming available online at an incredible rate. By displaying text data in a logical layout (e.g., color graphs), text visualization presents a direct way to observe the documents as well as understand the relationship between them. In this paper, we propose a novel technique, Exemplar-based visualization (EV), to visualize an extremely large text corpus. Capitalizing on recent advances in matrix approximation and decomposition, EV presents a probabilistic multidimensional projection model in the low-rank text subspace with a sound objective function. The probability of each document proportion to the topics is obtained through iterative optimization and embedded to a low dimensional space using parameter embedding. By selecting the representative exemplars, we obtain a compact approximation of the data. This makes the visualization highly efficient and flexible. In addition, the selected exemplars neatly summarize the entire data set and greatly reduce the cognitive overload in the visualization, leading to an easier interpretation of large text corpus. Empirically, we demonstrate the superior performance of EV through extensive experiments performed on the publicly available text data sets. Chen, Y. document text data visualisation 2009 matrix biology computing InfoVis color Visualization and Computer Graphics, IEEE Transactions on world wide web optimisation text visualization Wang, L. Dong, M. Hua, J. iterative methods exemplar-based visualization iterative optimization large document corpus matrix approximation parameter embedding text corpus exemplar large-scale document visualization multidimensional projection infovis09--5290724 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Visualizing the Intellectual Structure with Paper-Reference Matrices. Visualizing the intellectual structure of scientific domains using co-cited units such as references or authors has become a routine for domain analysis. In previous studies, paper-reference matrices are usually transformed into reference-reference matrices to obtain co-citation relationships, which are then visualized in different representations, typically as node-link networks, to represent the intellectual structures of scientific domains. Such network visualizations sometimes contain tightly knit components, which make visual analysis of the intellectual structure a challenging task. In this study, we propose a new approach to reveal co-citation relationships. Instead of using a reference-reference matrix, we directly use the original paper-reference matrix as the information source, and transform the paper-reference matrix into an FP-tree and visualize it in a Java-based prototype system. We demonstrate the usefulness of our approach through visual analyses of the intellectual structure of two domains: information visualization and Sloan Digital Sky Survey (SDSS). The results show that our visualization not only retains the major information of co-citation relationships, but also reveals more detailed sub-structures of tightly knit clusters than a conventional node-link network visualization. network data visualisation pattern clustering 2009 matrix visual analysis information visualization Chen, C. InfoVis Visualization and Computer Graphics, IEEE Transactions on citation analysis trees (mathematics) Java Zhang, J. Li, J. astronomical surveys astronomy computing network theory (graphs) scientific information systems FP-tree Java-based prototype system SDSS Sloan Digital Sky Survey author analysis co-citation relationship co-cited unit information source intellectual structure visualization node-link network visualization paper-reference matrix reference analysis reference-reference matrix scientific domain analysis tightly-knit cluster co-citation FP-tree intellectual structure paper-reference matrix infovis09--5290723 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Document Cards: A Top Trumps Visualization for Documents. Finding suitable, less space consuming views for a document's main content is crucial to provide convenient access to large document collections on display devices of different size. We present a novel compact visualization which represents the document's key semantic as a mixture of images and important key terms, similar to cards in a top trumps game. The key terms are extracted using an advanced text mining approach based on a fully automatic document structure extraction. The images and their captions are extracted using a graphical heuristic and the captions are used for a semi-semantic image weighting. Furthermore, we use the image color histogram for classification and show at least one representative from each non-empty image class. The approach is demonstrated for the IEEE InfoVis publications of a complete year. The method can easily be applied to other publication collections and sets of documents which contain images. document text Keim, D.A. Oelke, D. Stoffel, A. data visualisation 2009 data mining Rohrdantz, C. InfoVis color Visualization and Computer Graphics, IEEE Transactions on document image processing Deussen, O. document visualization Strobelt, H. IEEE InfoVis publications advanced text mining compact visualization display devices document cards document structure extraction image color histogram semi-semantic image weighting top trumps document visualization content extraction document collection browsing visual summary infovis09--5290722 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Participatory Visualization with Wordle. We discuss the design and usage of ldquoWordle,rdquo a Web-based tool for visualizing text. Wordle creates tag-cloud-like displays that give careful attention to typography, color, and composition. We describe the algorithms used to balance various aesthetic criteria and create the distinctive Wordle layouts. We then present the results of a study of Wordle usage, based both on spontaneous behaviour observed in the wild, and on a large-scale survey of Wordle users. The results suggest that Wordles have become a kind of medium of expression, and that a ldquoparticipatory culturerdquo has arisen around them. text data visualisation 2009 data analysis text analysis Wattenberg, M. Viegas, F.B. visualization Web sites InfoVis color Visualization and Computer Graphics, IEEE Transactions on social data analysis text tag cloud Feinberg, J. Web-based tool Wordle Wordle layouts tag-cloud-like displays text visualisation educational visualization memory participatory culture infovis09--5290721 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Visual Analysis of Inter-Process Communication for Large-Scale Parallel Computing. In serial computation, program profiling is often helpful for optimization of key sections of code. When moving to parallel computation, not only does the code execution need to be considered but also communication between the different processes which can induce delays that are detrimental to performance. As the number of processes increases, so does the impact of the communication delays on performance. For large-scale parallel applications, it is critical to understand how the communication impacts performance in order to make the code more efficient. There are several tools available for visualizing program execution and communications on parallel systems. These tools generally provide either views which statistically summarize the entire program execution or process-centric views. However, process-centric visualizations do not scale well as the number of processes gets very large. In particular, the most common representation of parallel processes is a Gantt chart with a row for each process. As the number of processes increases, these charts can become difficult to work with and can even exceed screen resolution. We propose a new visualization approach that affords more scalability and then demonstrate it on systems running with up to 16,384 processes. information visualization data visualisation 2009 Ma, K.-L. Muelder, C. visual analysis information visualization InfoVis Visualization and Computer Graphics, IEEE Transactions on application program interfaces Gygi, F. message passing Gantt chart MPI Profiling interprocess communication large-scale parallel computing parallel processes parallel systems program execution program profiling MPI Profiling scalability infovis09--5290720 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Protovis: A Graphical Toolkit for Visualization. Despite myriad tools for visualizing data, there remains a gap between the notational efficiency of high-level visualization systems and the expressiveness and accessibility of low-level graphical systems. Powerful visualization systems may be inflexible or impose abstractions foreign to visual thinking, while graphical systems such as rendering APIs and vector-based drawing programs are tedious for complex work. We argue that an easy-to-use graphical system tailored for visualization is needed. In response, we contribute Protovis, an extensible toolkit for constructing visualizations by composing simple graphical primitives. In Protovis, designers specify visualizations as a hierarchy of marks with visual properties defined as functions of data. This representation achieves a level of expressiveness comparable to low-level graphics systems, while improving efficiency - the effort required to specify a visualization - and accessibility - the effort required to learn and modify the representation. We substantiate this claim through a diverse collection of examples and comparative analysis with popular visualization tools. data visualisation 2009 Heer, J. hierarchy toolkit user interface InfoVis Visualization and Computer Graphics, IEEE Transactions on Bostock, M. toolkit information visualization data visualization rendering (computer graphics) application program interfaces Protovis graphical visualization toolkit high-level visualization systems low-level graphical systems rendering API vector-based drawing programs 2D graphics infovis09--5290719 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on A Multi-Threading Architecture to Support Interactive Visual Exploration. During continuous user interaction, it is hard to provide rich visual feedback at interactive rates for datasets containing millions of entries. The contribution of this paper is a generic architecture that ensures responsiveness of the application even when dealing with large data and that is applicable to most types of information visualizations. Our architecture builds on the separation of the main application thread and the visualization thread, which can be cancelled early due to user interaction. In combination with a layer mechanism, our architecture facilitates generating previews incrementally to provide rich visual feedback quickly. To help avoiding common pitfalls of multi-threading, we discuss synchronization and communication in detail. We explicitly denote design choices to control trade-offs. A quantitative evaluation based on the system VI S P L ORE shows fast visual feedback during continuous interaction even for millions of entries. We describe instantiations of our architecture in additional tools. interaction evaluation data visualisation 2009 user interfaces InfoVis Visualization and Computer Graphics, IEEE Transactions on software architecture Piringer, H. Tominski, C. Muigg, P. Berger, W. multi-threading VISPLORE continuous user interaction information visualizations interactive visual exploration multi-threading architecture visual feedback information visualization architecture continuous interaction layer multi-threading preview infovis09--5290718 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Towards Utilizing GPUs in Information Visualization: A Model and Implementation of Image-Space Operations. Modern programmable GPUs represent a vast potential in terms of performance and visual flexibility for information visualization research, but surprisingly few applications even begin to utilize this potential. In this paper, we conjecture that this may be due to the mismatch between the high-level abstract data types commonly visualized in our field, and the low-level floating-point model supported by current GPU shader languages. To help remedy this situation, we present a refinement of the traditional information visualization pipeline that is amenable to implementation using GPU shaders. The refinement consists of a final image-space step in the pipeline where the multivariate data of the visualization is sampled in the resolution of the current view. To concretize the theoretical aspects of this work, we also present a visual programming environment for constructing visualization shaders using a simple drag-and-drop interface. Finally, we give some examples of the use of shaders for well-known visualization techniques. data visualisation 2009 interaction information visualization Elmqvist, N. InfoVis Visualization and Computer Graphics, IEEE Transactions on McDonnel, B. visual programming abstract data types coprocessors GPU shader languages drag-and-drop interface high-level abstract data type image-space operation low-level floating-point model visual programming environment GPU-acceleration high-performance visualization shader programming infovis09--5290717 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on code_swarm: A Design Study in Organic Software Visualization. In May of 2008, we published online a series of software visualization videos using a method called code_swarm. Shortly thereafter, we made the code open source and its popularity took off. This paper is a study of our code swarm application, comprising its design, results and public response. We share our design methodology, including why we chose the organic information visualization technique, how we designed for both developers and a casual audience, and what lessons we learned from our experiment. We validate the results produced by code_swarm through a qualitative analysis and by gathering online user comments. Furthermore, we successfully released the code as open source, and the software community used it to visualize their own projects and shared their results as well. In the end, we believe code_swarm has positive implications for the future of organic information design and open source information visualization practice. data visualisation 2009 Ma, K.-L. experiment InfoVis Visualization and Computer Graphics, IEEE Transactions on design study software visualization design methodology Ogawa, M. public domain software software maintenance video signal processing code_swarm open source information visualization practice organic information design organic information visualization technique organic software visualization software development evolution software development history software visualization videos software visualization organic information visualization software development history and evolution infovis09--5290716 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on SpicyNodes: Radial Layout Authoring for the General Public. Trees and graphs are relevant to many online tasks such as visualizing social networks, product catalogs, educational portals, digital libraries, the semantic web, concept maps and personalized information management. SpicyNodes is an information-visualization technology that builds upon existing research on radial tree layouts and graph structures. Users can browse a tree, clicking from node to node, as well as successively viewing a node, immediately related nodes and the path back to the ldquohomerdquo nodes. SpicyNodes' layout algorithms maintain balanced layouts using a hybrid mixture of a geometric layout (a succession of spanning radial trees) and force-directed layouts to minimize overlapping nodes, plus several other improvements over prior art. It provides XML-based API and GUI authoring tools. The goal of the SpicyNodes project is to implement familiar principles of radial maps and focus+context with an attractive and inviting look and feel in an open system that is accessible to virtually any Internet user. social graph Liu, S. data visualisation 2009 interaction information visualization radial InfoVis Visualization and Computer Graphics, IEEE Transactions on focus+context focus+context trees (mathematics) human-computer interaction graph structures hierarchy visualization Douma, M. Ligierko, G. Ancuta, O. Gritsai, P. authoring systems GUI authoring tools SpicyNodes XML-based API force-directed layouts geometric layout information-visualization technology radial layout authoring radial tree layouts trees and network visualization radial tree layout infovis09--5290715 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Harnessing the Information Ecosystem with Wiki-based Visualization Dashboards. We describe the design and deployment of Dashiki, a public Website where users may collaboratively build visualization dashboards through a combination of a wiki-like syntax and interactive editors. Our goals are to extend existing research on social data analysis into presentation and organization of data from multiple sources, explore new metaphors for these activities, and participate more fully in the Web's information ecology by providing tighter integration with real-time data. To support these goals, our design includes novel and low-barrier mechanisms for editing and layout of dashboard pages and visualizations, connection to data sources, and coordinating interaction between visualizations. In addition to describing these technologies, we provide a preliminary report on the public launch of a prototype based on this design, including a description of the activities of our users derived from observation and interviews. interaction visual analytics visualization collaboration social data visualisation 2009 data analysis Internet InfoVis Visualization and Computer Graphics, IEEE Transactions on social data analysis social networking (online) McKeon, M. Dashiki Web information ecology Web information ecosystem Wiki-based visualization dashboards coordinating interaction dashboard pages public Web site social data analysis wiki-like syntax dashboards social software web wikis infovis09--5290714 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on The Benefits of Synchronous Collaborative Information Visualization: Evidence from an Experimental Evaluation. A great corpus of studies reports empirical evidence of how information visualization supports comprehension and analysis of data. The benefits of visualization for synchronous group knowledge work, however, have not been addressed extensively. Anecdotal evidence and use cases illustrate the benefits of synchronous collaborative information visualization, but very few empirical studies have rigorously examined the impact of visualization on group knowledge work. We have consequently designed and conducted an experiment in which we have analyzed the impact of visualization on knowledge sharing in situated work groups. Our experimental study consists of evaluating the performance of 131 subjects (all experienced managers) in groups of 5 (for a total of 26 groups), working together on a real-life knowledge sharing task. We compare (1) the control condition (no visualization provided), with two visualization supports: (2) optimal and (3) suboptimal visualization (based on a previous survey). The facilitator of each group was asked to populate the provided interactive visual template with insights from the group, and to organize the contributions according to the group consensus. We have evaluated the results through both objective and subjective measures. Our statistical analysis clearly shows that interactive visualization has a statistically significant, objective and positive impact on the outcomes of knowledge sharing, but that the subjects seem not to be aware of this. In particular, groups supported by visualization achieved higher productivity, higher quality of outcome and greater knowledge gains. No statistically significant results could be found between an optimal and a suboptimal visualization though (as classified by the pre-experiment survey). Subjects also did not seem to be aware of the benefits that the visualizations provided as no difference between the visualization and the control conditions was found for the self-reported measures of satisfaction a- nd participation. An implication of our study for information visualization applications is to extend them by using real-time group annotation functionalities that aid in the group sense making process of the represented data. evaluation visual knowledge representation data visualisation 2009 data analysis statistical analysis experiment InfoVis Visualization and Computer Graphics, IEEE Transactions on experiment Bresciani, S. Eppler, M.J. group annotation knowledge sharing suboptimal visualization synchronous collaborative information visualization synchronous group knowledge work collaborative and distributed visualization laboratory study group work knowledge sharing synchronous situated collaboration infovis09--5290713 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Lark: Coordinating Co-located Collaboration with Information Visualization. Large multi-touch displays are expanding the possibilities of multiple-coordinated views by allowing multiple people to interact with data in concert or independently. We present Lark, a system that facilitates the coordination of interactions with information visualizations on shared digital workspaces. We focus on supporting this coordination according to four main criteria: scoped interaction, temporal flexibility, spatial flexibility, and changing collaboration styles. These are achieved by integrating a representation of the information visualization pipeline into the shared workspace, thus explicitly indicating coordination points on data, representation, presentation, and view levels. This integrated meta-visualization supports both the awareness of how views are linked and the freedom to work in concert or independently. Lark incorporates these four main criteria into a coherent visualization collaboration interaction environment by providing direct visual and algorithmic support for the coordination of data analysis actions over shared large displays. interaction collaboration Isenberg, P. coordinated views data visualisation 2009 data analysis information visualization awareness InfoVis Visualization and Computer Graphics, IEEE Transactions on Carpendale, S. information visualization Tobiasz, M. touch sensitive screens Lark colocated collaboration integrated meta-visualization multitouch displays scoped interaction spatial flexibility temporal flexibility co-located work collaboration coordination meta-visualization workspace awareness infovis09--5290712 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on ResultMaps: Visualization for Search Interfaces. Hierarchical representations are common in digital repositories, yet are not always fully leveraged in their online search interfaces. This work describes ResultMaps, which use hierarchical treemap representations with query string-driven digital library search engines. We describe two lab experiments, which find that ResultsMap users yield significantly better results over a control condition on some subjective measures, and we find evidence that ResultMaps have ancillary benefits via increased understanding of some aspects of repository content. The ResultMap system and experiments contribute an understanding of the benefits-direct and indirect-of the ResultMap approach to repository search visualization. data visualisation 2009 user interfaces evaluation digital library InfoVis Visualization and Computer Graphics, IEEE Transactions on treemap query processing digital libraries trees (mathematics) treemap user study Clarkson, E. Desai, K. Foley, J. search engines ResultMap system digital repositories hierarchical treemap representations online search interfaces query string-driven digital library search engines repository search visualization digital repository infovis search engine search visualization infovis09--5290711 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Temporal Summaries: Supporting Temporal Categorical Searching, Aggregation and Comparison. When analyzing thousands of event histories, analysts often want to see the events as an aggregate to detect insights and generate new hypotheses about the data. An analysis tool must emphasize both the prevalence and the temporal ordering of these events. Additionally, the analysis tool must also support flexible comparisons to allow analysts to gather visual evidence. In a previous work, we introduced align, rank, and filter (ARF) to accentuate temporal ordering. In this paper, we present temporal summaries, an interactive visualization technique that highlights the prevalence of event occurrences. Temporal summaries dynamically aggregate events in multiple granularities (year, month, week, day, hour, etc.) for the purpose of spotting trends over time and comparing several groups of records. They provide affordances for analysts to perform temporal range filters. We demonstrate the applicability of this approach in two extensive case studies with analysts who applied temporal summaries to search, filter, and look for patterns in electronic health records and academic records. information visualization data visualisation 2009 categorical Shneiderman, B. filter Plaisant, C. human computer interaction InfoVis Visualization and Computer Graphics, IEEE Transactions on interaction design Wang, T.D. Spring, N. Roseman, D. Marchand, G. Mukherjee, V. Smith, M. interactive visualization technique temporal categorical searching temporal ordering temporal summaries human-computer interaction temporal categorical data visualization infovis09--5290710 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Flow Mapping and Multivariate Visualization of Large Spatial Interaction Data. Spatial interactions (or flows), such as population migration and disease spread, naturally form a weighted location-to-location network (graph). Such geographically embedded networks (graphs) are usually very large. For example, the county-to-county migration data in the U.S. has thousands of counties and about a million migration paths. Moreover, many variables are associated with each flow, such as the number of migrants for different age groups, income levels, and occupations. It is a challenging task to visualize such data and discover network structures, multivariate relations, and their geographic patterns simultaneously. This paper addresses these challenges by developing an integrated interactive visualization framework that consists three coupled components: (1) a spatially constrained graph partitioning method that can construct a hierarchy of geographical regions (communities), where there are more flows or connections within regions than across regions; (2) a multivariate clustering and visualization method to detect and present multivariate patterns in the aggregated region-to-region flows; and (3) a highly interactive flow mapping component to map both flow and multivariate patterns in the geographic space, at different hierarchical levels. The proposed approach can process relatively large data sets and effectively discover and visualize major flow structures and multivariate relations at the same time. User interactions are supported to facilitate the understanding of both an overview and detailed patterns. interaction geographic network graph clustering overview data visualisation 2009 user interfaces hierarchy data mining InfoVis Visualization and Computer Graphics, IEEE Transactions on cartography multidimensional visualization Guo, D. hierarchical clustering coordinated views graph partitioning county-to-county migration data geographic space integrated interactive visualization framework interactive flow mapping large spatial interaction data multivariate clustering multivariate visualization spatially constrained graph partitioning method weighted location-to-location network contiguity constraints flow mapping spatial interaction infovis09--5290709 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Comparing Dot and Landscape Spatializations for Visual Memory Differences. Spatialization displays use a geographic metaphor to arrange non-spatial data. For example, spatializations are commonly applied to document collections so that document themes appear as geographic features such as hills. Many common spatialization interfaces use a 3-D landscape metaphor to present data. However, it is not clear whether 3-D spatializations afford improved speed and accuracy for user tasks compared to similar 2-D spatializations. We describe a user study comparing users' ability to remember dot displays, 2-D landscapes, and 3-D landscapes for two different data densities (500 vs. 1000 points). Participants' visual memory was statistically more accurate when viewing dot displays and 3-D landscapes compared to 2-D landscapes. Furthermore, accuracy remembering a spatialization was significantly better overall for denser spatializations. Theseresults are of benefit to visualization designers who are contemplating the best ways to present data using spatialization techniques. user study Tory, M. geographic document data visualisation 2009 InfoVis Visualization and Computer Graphics, IEEE Transactions on Swindells, C. document handling Dreezer, R. 2D landscapes 3D landscapes document collections dot displays dot spatializations geographic metaphor landscape spatializations nonspatial data spatialization displays spatialization interfaces visual memory differences information interfaces and presentation evaluation / methodology landscape visualization screen design software psychology user / machine systems infovis09--5290708 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on SellTrend: Inter-Attribute Visual Analysis of Temporal Transaction Data. We present a case study of our experience designing SellTrend, a visualization system for analyzing airline travel purchase requests. The relevant transaction data can be characterized as multi-variate temporal and categorical event sequences, and the chief problem addressed is how to help company analysts identify complex combinations of transaction attributes that contribute to failed purchase requests. SellTrend combines a diverse set of techniques ranging from time series visualization to faceted browsing and historical trend analysis in order to help analysts make sense of the data. We believe that the combination of views and interaction capabilities in SellTrend provides an innovative approach to this problem and to other similar types of multivariate, temporally driven transaction data analysis. Initial feedback from company analysts confirms the utility and benefits of the system. interaction Liu, Z. case study time series data visualisation 2009 categorical data analysis Stasko, J. information visualization multiple views investigative analysis InfoVis Visualization and Computer Graphics, IEEE Transactions on categorical data time series time series data Sullivan, T. travel industry SellTrend airline travel purchase requests categorical event sequences historical trend analysis inter-attribute visual analysis multi-variate temporal event sequences temporal transaction data analysis time series visualization multiple attributes transaction analysis infovis09--5290707 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on FromDaDy: Spreading Aircraft Trajectories Across Views to Support Iterative Queries. When displaying thousands of aircraft trajectories on a screen, the visualization is spoiled by a tangle of trails. The visual analysis is therefore difficult, especially if a specific class of trajectories in an erroneous dataset has to be studied. We designed FromDaDy, a trajectory visualization tool that tackles the difficulties of exploring the visualization of multiple trails. This multidimensional data exploration is based on scatterplots, brushing, pick and drop, juxtaposed views and rapid visual design. Users can organize the workspace composed of multiple juxtaposed views. They can define the visual configuration of the views by connecting data dimensions from the dataset to Bertin's visual variables. They can then brush trajectories, and with a pick and drop operation they can spread the brushed information across views. They can then repeat these interactions, until they extract a set of relevant data, thus formulating complex queries. Through two real-world scenarios, we show how FromDaDy supports iterative queries and the extraction of trajectories in a dataset that contains up to 5 million data. visualization data visualisation 2009 trajectories visual analysis brushing InfoVis direct manipulation Visualization and Computer Graphics, IEEE Transactions on query processing air traffic Hurter, C. Tissoires, B. Conversy, S. FromDaDy aircraft trajectories iterative queries multidimensional data exploration pick and drop operation trajectory visualization tool iterative exploration infovis09--5290706 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Bubble Sets: Revealing Set Relations with Isocontours over Existing Visualizations. While many data sets contain multiple relationships, depicting more than one data relationship within a single visualization is challenging. We introduce Bubble Sets as a visualization technique for data that has both a primary data relation with a semantically significant spatial organization and a significant set membership relation in which members of the same set are not necessarily adjacent in the primary layout. In order to maintain the spatial rights of the primary data relation, we avoid layout adjustment techniques that improve set cluster continuity and density. Instead, we use a continuous, possibly concave, isocontour to delineate set membership, without disrupting the primary layout. Optimizations minimize cluster overlap and provide for calculation of the isocontours at interactive speeds. Case studies show how this technique can be used to indicate multiple sets on a variety of common visualizations. cluster data visualisation clustering 2009 Collins, C. tree visualization InfoVis Visualization and Computer Graphics, IEEE Transactions on Carpendale, S. data visualization graph visualization data sets Penn, G. set theory Bubble sets data relationship isocontours primary data relation set cluster continuity set relation spatial layout infovis09--5290705 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Scattering Points in Parallel Coordinates. In this paper, we present a novel parallel coordinates design integrated with points (scattering points in parallel coordinates, SPPC), by taking advantage of both parallel coordinates and scatterplots. Different from most multiple views visualization frameworks involving parallel coordinates where each visualization type occupies an individual window, we convert two selected neighboring coordinate axes into a scatterplot directly. Multidimensional scaling is adopted to allow converting multiple axes into a single subplot. The transition between two visual types is designed in a seamless way. In our work, a series of interaction tools has been developed. Uniform brushing functionality is implemented to allow the user to perform data selection on both points and parallel coordinate polylines without explicitly switching tools. A GPU accelerated dimensional incremental multidimensional scaling (DIMDS) has been developed to significantly improve the system performance. Our case study shows that our scheme is more efficient than traditional multi-view methods in performing visual analysis tasks. interaction case study scatterplot parallel coordinates data visualisation 2009 multiple views brushing parallel coordinates InfoVis Visualization and Computer Graphics, IEEE Transactions on Qu, H. Zhou, H. data visualization multidimensional scaling Yuan, X. Guo, P. Xiao, H. GPU data selection dimensional incremental multidimensional scaling scattering points visual analysis tasks dimensionality reduction interactivity quality metrics variable ordering infovis09--5290704 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Interactive Dimensionality Reduction Through User-defined Combinations of Quality Metrics. Multivariate data sets including hundreds of variables are increasingly common in many application areas. Most multivariate visualization techniques are unable to display such data effectively, and a common approach is to employ dimensionality reduction prior to visualization. Most existing dimensionality reduction systems focus on preserving one or a few significant structures in data. For many analysis tasks, however, several types of structures can be of high significance and the importance of a certain structure compared to the importance of another is often task-dependent. This paper introduces a system for dimensionality reduction by combining user-defined quality metrics using weight functions to preserve as many important structures as possible. The system aims at effective visualization and exploration of structures within large multivariate data sets and provides enhancement of diverse structures by supplying a range of automatic variable orderings. Furthermore it enables a quality-guided reduction of variables through an interactive display facilitating investigation of trade-offs between loss of structure and the number of variables to keep. The generality and interactivity of the system is demonstrated through a case scenario. information visualization data visualisation interactive systems 2009 metrics InfoVis Visualization and Computer Graphics, IEEE Transactions on parallel coordinates Johansson, J. Johansson, S. data reduction interactive dimensionality reduction multivariate data sets multivariate visualization technique quality metrics user-defined combinations multidimensional scaling scatterplot infovis09--5290703 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Visualizing Social Photos on a Hasse Diagram for Eliciting Relations and Indexing New Photos. Social photos, which are taken during family events or parties, represent individuals or groups of people. We show in this paper how a Hasse diagram is an efficient visualization strategy for eliciting different groups and navigating through them. However, we do not limit this strategy to these traditional uses. Instead we show how it can also be used for assisting in indexing new photos. Indexing consists of identifying the event and people in photos. It is an integral phase that takes place before searching and sharing. In our method we use existing indexed photos to index new photos. This is performed through a manual drag and drop procedure followed by a content fusion process that we call 'propagation'. At the core of this process is the necessity to organize and visualize the photos that will be used for indexing in a manner that is easily recognizable and accessible by the user. In this respect we make use of an object Galois sub-hierarchy and display it using a Hasse diagram. The need for an incremental display that maintains the user's mental map also leads us to propose a novel way of building the Hasse diagram. To validate the approach, we present some tests conducted with a sample of users that confirm the interest of this organization, visualization and indexation approach. Finally, we conclude by considering scalability, the possibility to extract social networks and automatically create personalised albums. social data visualisation 2009 data analysis information visualization human computer interaction hierarchy InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization social networking (online) Crampes, M. de Oliveira-Kumar, J. Ranwez, S. Villerd, J. Galois fields indexing Hasse diagram content fusion process eliciting relations formal concept analysis indexing new photos object Galois sub-hierarchy social photos visualization strategy Galois sub-hierarchy hasse diagram formal concept analysis indexation social photos infovis09--5290702 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Configuring Hierarchical Layouts to Address Research Questions. We explore the effects of selecting alternative layouts in hierarchical displays that show multiple aspects of large multivariate datasets, including spatial and temporal characteristics. Hierarchical displays of this type condition a dataset by multiple discrete variable values, creating nested graphical summaries of the resulting subsets in which size, shape and colour can be used to show subset properties. These 'small multiples' are ordered by the conditioning variable values and are laid out hierarchically using dimensional stacking. Crucially, we consider the use of different layouts at different hierarchical levels, so that the coordinates of the plane can be used more effectively to draw attention to trends and anomalies in the data. We argue that these layouts should be informed by the type of conditioning variable and by the research question being explored. We focus on space-filling rectangular layouts that provide data-dense and rich overviews of data to address research questions posed in our exploratory analysis of spatial and temporal aspects of property sales in London. We develop a notation ('HiVE') that describes visualisation and layout states and provides reconfiguration operators, demonstrate its use for reconfiguring layouts to pursue research questions and provide guidelines for this process. We demonstrate how layouts can be related through animated transitions to reduce the cognitive load associated with their reconfiguration whilst supporting the exploratory process. data visualisation 2009 visual databases geovisualization InfoVis Visualization and Computer Graphics, IEEE Transactions on small multiples Dykes, J. Slingsby, A. Wood, J. dimensional stacking layout geography temporal databases cognitive load hierarchical displays hierarchical layouts multivariate datasets research questions space-filling rectangular layouts exploratory guidelines hierarchical notation infovis09--5290701 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Smooth Graphs for Visual Exploration of Higher-Order State Transitions. In this paper, we present a new visual way of exploring state sequences in large observational time-series. A key advantage of our method is that it can directly visualize higher-order state transitions. A standard first order state transition is a sequence of two states that are linked by a transition. A higher-order state transition is a sequence of three or more states where the sequence of participating states are linked together by consecutive first order state transitions. Our method extends the current state-graph exploration methods by employing a two dimensional graph, in which higher-order state transitions are visualized as curved lines. All transitions are bundled into thick splines, so that the thickness of an edge represents the frequency of instances. The bundling between two states takes into account the state transitions before and after the transition. This is done in such a way that it forms a continuous representation in which any subsequence of the timeseries is represented by a continuous smooth line. The edge bundles in these graphs can be explored interactively through our incremental selection algorithm. We demonstrate our method with an application in exploring labeled time-series data from a biological survey, where a clustering has assigned a single label to the data at each time-point. In these sequences, a large number of cyclic patterns occur, which in turn are linked to specific activities. We demonstrate how our method helps to find these cycles, and how the interactive selection process helps to find and investigate activities. graph clustering 2009 graph theory biology computing InfoVis Visualization and Computer Graphics, IEEE Transactions on graph drawing time series Blaas, J. Botha, C. Grundy, E. Jones, M. Laramee, R.S. Post, F. splines (mathematics) biological data higher-order state transitions large observational time series smooth graphs splines state sequences state-graph exploration methods biological data state transitions time series infovis09--5290700 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on A Comparison of User-Generated and Automatic Graph Layouts. The research presented in this paper compares user-generated and automatic graph layouts. Following the methods suggested by van Ham et al. (2008), a group of users generated graph layouts using both multi-touch interaction on a tabletop display and mouse interaction on a desktop computer. Users were asked to optimize their layout for aesthetics and analytical tasks with a social network. We discuss characteristics of the user-generated layouts and interaction methods employed by users in this process. We then report on a web-based study to compare these layouts with the output of popular automatic layout algorithms. Our results demonstrate that the best of the user-generated layouts performed as well as or better than the physics-based layout. Orthogonal and circular automatic layouts were found to be considerably less effective than either the physics-based layout or the best of the user-generated layouts. We highlight several attributes of the various layouts that led to high accuracy and improved task completion time, as well as aspects in which traditional automatic layout methods were unsuccessful for our tasks. interaction Fisher, D. Isenberg, P. social network Lee, B. graph North, C. 2009 user interfaces graph theory Robertson, G. InfoVis Visualization and Computer Graphics, IEEE Transactions on network layout Dwyer, T. aesthetics graph layout social networking (online) Quinn, K.I. automatic graph layout circular automatic layouts desktop computer mouse interaction multitouch interaction orthogonal automatic layouts physics-based layout tabletop display user-generated layouts automatic layout algorithms graph-drawing aesthetics user-generated layout infovis09--5290699 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on ?Search, Show Context, Expand on Demand?: Supporting Large Graph Exploration with Degree-of-Interest. A common goal in graph visualization research is the design of novel techniques for displaying an overview of an entire graph. However, there are many situations where such an overview is not relevant or practical for users, as analyzing the global structure may not be related to the main task of the users that have semi-specific information needs. Furthermore, users accessing large graph databases through an online connection or users running on less powerful (mobile) hardware simply do not have the resources needed to compute these overviews. In this paper, we advocate an interaction model that allows users to remotely browse the immediate context graph around a specific node of interest. We show how Furnas' original degree of interest function can be adapted from trees to graphs and how we can use this metric to extract useful contextual subgraphs, control the complexity of the generated visualization and direct users to interesting datapoints in the context. We demonstrate the effectiveness of our approach with an exploration of a dense online database containing over 3 million legal citations. interaction graph overview data visualisation 2009 graph theory mathematics computing database hardware network visualization InfoVis Visualization and Computer Graphics, IEEE Transactions on van Ham, F. focus+context citation analysis graph visualization Perer, A. contextual subgraph dense online database graph visualization immediate context graph large graph database large graph exploration legal citation degree of interest legal citation networks infovis09--5290698 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on ActiviTree: Interactive Visual Exploration of Sequences in Event-Based Data Using Graph Similarity. The identification of significant sequences in large and complex event-based temporal data is a challenging problem with applications in many areas of today's information intensive society. Pure visual representations can be used for the analysis, but are constrained to small data sets. Algorithmic search mechanisms used for larger data sets become expensive as the data size increases and typically focus on frequency of occurrence to reduce the computational complexity, often overlooking important infrequent sequences and outliers. In this paper we introduce an interactive visual data mining approach based on an adaptation of techniques developed for Web searching, combined with an intuitive visual interface, to facilitate user-centred exploration of the data and identification of sequences significant to that user. The search algorithm used in the exploration executes in negligible time, even for large data, and so no pre-processing of the selected data is required, making this a completely interactive experience for the user. Our particular application area is social science diary data but the technique is applicable across many other disciplines. social graph 2009 data mining graph theory data mining InfoVis Visualization and Computer Graphics, IEEE Transactions on computational complexity Johansson, J. Cooper, M. Vrotsou, K. ActiviTree Web searching algorithmic search mechanisms complex event-based temporal data event-based data graph similarity interactive visual data mining interactive visual sequence exploration event-based data graph similarity interactive visual exploration node similarity sequence identification infovis09--5290697 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Interaction Techniques for Selecting and Manipulating Subgraphs in Network Visualizations. We present a novel and extensible set of interaction techniques for manipulating visualizations of networks by selecting subgraphs and then applying various commands to modify their layout or graphical properties. Our techniques integrate traditional rectangle and lasso selection, and also support selecting a node's neighbourhood by dragging out its radius (in edges) using a novel kind of radial menu. Commands for translation, rotation, scaling, or modifying graphical properties (such as opacity) and layout patterns can be performed by using a hotbox (a transiently popped-up, semi-transparent set of widgets) that has been extended in novel ways to integrate specification of commands with 1D or 2D arguments. Our techniques require only one mouse button and one keyboard key, and are designed for fast, gestural, in-place interaction. We present the design and integration of these interaction techniques, and illustrate their use in interactive graph visualization. Our techniques are implemented in NAViGaTOR, a software package for visualizing and analyzing biological networks. An initial usability study is also reported. interaction network graph usability data visualisation interactive systems 2009 graph theory biology computing radial InfoVis Visualization and Computer Graphics, IEEE Transactions on McGuffin, M.J. network layout Jurisica, I. interactive graph drawing interaction techniques usability study NAViGaTOR biological networks interactive graph visualization lasso selection network visualizations selecting subgraphs software package biological networks hotbox marking menus radial menu infovis09--5290696 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Conjunctive Visual Forms. Visual exploration of multidimensional data is a process of isolating and extracting relationships within and between dimensions. Coordinated multiple view approaches are particularly effective for visual exploration because they support precise expression of heterogeneous multidimensional queries using simple interactions. Recent visual analytics research has made significant progress in identifying and understanding patterns of composed views and coordinations that support fast, flexible, and open-ended data exploration. What is missing is formalization of the space of expressible queries in terms of visual representation and interaction. This paper introduces the conjunctive visual form model in which visual exploration consists of interactively-driven sequences of transitions between visual states that correspond to conjunctive normal forms in boolean logic. The model predicts several new and useful ways to extend the space of rapidly expressible queries through addition of simple interactive capabilities to existing compositional patterns. Two recent related visual tools offer a subset of these capabilities, providing a basis for conjecturing about such extensions. interaction visual analytics Weaver, C. data visualisation 2009 visual representation multiple views InfoVis Visualization and Computer Graphics, IEEE Transactions on brushing query processing exploratory visualization boolean logic conjunctive visual form model heterogeneous multidimensional queries multidimensional data visual exploration boolean query conjunctive normal form visual abstraction infovis09--5290695 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on A Nested Process Model for Visualization Design and Validation. We present a nested model for the visualization design and validation with four layers: characterize the task and data in the vocabulary of the problem domain, abstract into operations and data types, design visual encoding and interaction techniques, and create algorithms to execute techniques efficiently. The output from a level above is input to the level below, bringing attention to the design challenge that an upstream error inevitably cascades to all downstream levels. This model provides prescriptive guidance for determining appropriate evaluation approaches by identifying threats to validity unique to each level. We also provide three recommendations motivated by this model: authors should distinguish between these levels when claiming contributions at more than one of them, authors should explicitly state upstream assumptions at levels above the focus of a paper, and visualization venues should accept more papers on domain characterization. interaction evaluation Munzner, T. data visualisation 2009 evaluation design InfoVis Visualization and Computer Graphics, IEEE Transactions on domain characterization nested process model visual encoding visualization design models framework infovis09--5290694 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Spatiotemporal Analysis of Sensor Logs using Growth Ring Maps. Spatiotemporal analysis of sensor logs is a challenging research field due to three facts: a) traditional two-dimensional maps do not support multiple events to occur at the same spatial location, b) three-dimensional solutions introduce ambiguity and are hard to navigate, and c) map distortions to solve the overlap problem are unfamiliar to most users. This paper introduces a novel approach to represent spatial data changing over time by plotting a number of non-overlapping pixels, close to the sensor positions in a map. Thereby, we encode the amount of time that a subject spent at a particular sensor to the number of plotted pixels. Color is used in a twofold manner; while distinct colors distinguish between sensor nodes in different regions, the colors' intensity is used as an indicator to the temporal property of the subjects' activity. The resulting visualization technique, called growth ring maps, enables users to find similarities and extract patterns of interest in spatiotemporal data by using humans' perceptual abilities. We demonstrate the newly introduced technique on a dataset that shows the behavior of healthy and Alzheimer transgenic, male and female mice. We motivate the new technique by showing that the temporal analysis based on hierarchical clustering and the spatial analysis based on transition matrices only reveal limited results. Results and findings are cross-validated using multidimensional scaling. While the focus of this paper is to apply our visualization for monitoring animal behavior, the technique is also applicable for analyzing data, such as packet tracing, geographic monitoring of sales development, or mobile phone capacity planning. visual analytics geographic Keim, D.A. clustering data visualisation 2009 biology computing Janetzko, H. Bak, P. Mansmann, F. InfoVis color Visualization and Computer Graphics, IEEE Transactions on colour graphics hierarchical clustering visualization technique multidimensional scaling biosensors data loggers Alzheimer transgenic mice colors intensity distinct colors geographic monitoring growth ring maps map distortions mobile phone capacity planning nonoverlapping pixels packet tracing sensor logs spatiotemporal analysis spatial data animal behavior dense pixel displays spatiotemporal visualization infovis09--5290693 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on GeneShelf: A Web-based Visual Interface for Large Gene Expression Time-Series Data Repositories. A widespread use of high-throughput gene expression analysis techniques enabled the biomedical research community to share a huge body of gene expression datasets in many public databases on the web. However, current gene expression data repositories provide static representations of the data and support limited interactions. This hinders biologists from effectively exploring shared gene expression datasets. Responding to the growing need for better interfaces to improve the utility of the public datasets, we have designed and developed a new web-based visual interface entitled GeneShelf (http://bioinformatics.cnmcresearch.org/GeneShelf). It builds upon a zoomable grid display to represent two categorical dimensions. It also incorporates an augmented timeline with expandable time points that better shows multiple data values for the focused time point by embedding bar charts. We applied GeneShelf to one of the largest microarray datasets generated to study the progression and recovery process of injuries at the spinal cord of mice and rats. We present a case study and a preliminary qualitative user study with biologists to show the utility and usability of GeneShelf. user study Lee, B. case study usability 2009 categorical Internet user interfaces biology computing genetics bioinformatics animation InfoVis Seo, J. Visualization and Computer Graphics, IEEE Transactions on Kim, B. data structures Hoffman, E. Knoblach, S. GeneShelf Web-based visual interface bar charts large gene expression time-series data repositories public databases static data representations augmented timeline bioinformatics visualization gene expression profiling zoomable grid infovis09--5290692 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on MizBee: A Multiscale Synteny Browser. In the field of comparative genomics, scientists seek to answer questions about evolution and genomic function by comparing the genomes of species to find regions of shared sequences. Conserve dsyntenic blocks are an important biological data abstraction for indicating regions of shared sequences. The goal of this work is to show multiple types of relationships at multiple scales in a way that is visually comprehensible in accordance with known perceptual principles. We present a task analysis for this domain where the fundamental questions asked by biologists can be understood by a characterization of relationships into the four types of proximity/location, size, orientation, and similarity/strength, and the four scales of genome, chromosome, block, and genomic feature. We also propose a new taxonomy of the design space for visually encoding conservation data. We present MizBee, a multiscale synteny browser with the unique property of providing interactive side-by-side views of the data across the range of scales supporting exploration of all of these relationship types. We conclude with case studies from two biologists who used MizBee to augment their previous automatic analysis work flow, providing anecdotal evidence about the efficacy of the system for the visualization of syntenic data, the analysis of conservation relationships, and the communication of scientific insights. Munzner, T. data visualisation 2009 biology computing bioinformatics taxonomy InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization design study Meyer, M. Pfister, H. genomics data structures data visualization MizBee biological data abstraction chromosome comparative genomics dsyntenic blocks genome multiscale synteny browser synteny infovis09--5290691 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on Constructing Overview + Detail Dendrogram-Matrix Views. A dendrogram that visualizes a clustering hierarchy is often integrated with a re-orderable matrix for pattern identification. The method is widely used in many research fields including biology, geography, statistics, and data mining. However, most dendrograms do not scale up well, particularly with respect to problems of graphical and cognitive information overload. This research proposes a strategy that links an overview dendrogram and a detail-view dendrogram, each integrated with a re-orderable matrix. The overview displays only a user-controlled, limited number of nodes that represent the ldquoskeletonrdquo of a hierarchy. The detail view displays the sub-tree represented by a selected meta-node in the overview. The research presented here focuses on constructing a concise overview dendrogram and its coordination with a detail view. The proposed method has the following benefits: dramatic alleviation of information overload, enhanced scalability and data abstraction quality on the dendrogram, and the support of data exploration at arbitrary levels of detail. The contribution of the paper includes a new metric to measure the ldquoimportancerdquo of nodes in a dendrogram; the method to construct the concise overview dendrogram from the dynamically-identified, important nodes; and measure for evaluating the data abstraction quality for dendrograms. We evaluate and compare the proposed method to some related existing methods, and demonstrating how the proposed method can help users find interesting patterns through a case study on county-level U.S. cervical cancer mortality and demographic data. case study clustering overview pattern clustering 2009 matrix data mining statistics hierarchy MacEachren, A.M. InfoVis Visualization and Computer Graphics, IEEE Transactions on data structures Chen, J. Peuquet, D.J. matrix algebra clustering hierarchy data abstraction quality data exploration dendrogram-matrix views detail view dendrogram overview dendrogram pattern identification reorderable matrix dendrogram compound graph data abstraction quality metrics hierarchical clusters reorderable matrix infovis09--5290690 10/14/2009 Visualization and Computer Graphics, IEEE Transactions on ABySS-Explorer: Visualizing Genome Sequence Assemblies. One bottleneck in large-scale genome sequencing projects is reconstructing the full genome sequence from the short subsequences produced by current technologies. The final stages of the genome assembly process inevitably require manual inspection of data inconsistencies and could be greatly aided by visualization. This paper presents our design decisions in translating key data features identified through discussions with analysts into a concise visual encoding. Current visualization tools in this domain focus on local sequence errors making high-level inspection of the assembly difficult if not impossible. We present a novel interactive graph display, ABySS-Explorer, that emphasizes the global assembly structure while also integrating salient data features such as sequence length. Our tool replaces manual and in some cases pen-and-paper based analysis tasks, and we discuss how user feedback was incorporated into iterative design refinements. Finally, we touch on applications of this representation not initially considered in our design phase, suggesting the generality of this encoding for DNA sequence data. graph data visualisation interactive systems 2009 bioinformatics InfoVis Visualization and Computer Graphics, IEEE Transactions on design study visualization tools genomics Nielsen, C.B. Jackman, S.D. Birol, I. Jones, S.J.M. DNA ABySS-Explorer DNA sequence data bioinformatics visualization genome assembly process genome sequence assemblies genome sequencing projects interactive graph display pen-and-paper based analysis tasks user feedback bioinformatics visualization DNA sequence genome assembly infovis10--180 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Necklace Maps. Statistical data associated with geographic regions is nowadays globally available in large amounts and hence automated methods to visually display these data are in high demand. There are several well-established thematic map types for quantitative data on the ratio-scale associated with regions: choropleth maps, cartograms, and proportional symbol maps. However, all these maps suffer from limitations, especially if large data values are associated with small regions. To overcome these limitations, we propose a novel type of quantitative thematic map, the necklace map. In a necklace map, the regions of the underlying two-dimensional map are projected onto intervals on a one-dimensional curve (the necklace) that surrounds the map regions. Symbols are scaled such that their area corresponds to the data of their region and placed without overlap inside the corresponding interval on the necklace. Necklace maps appear clear and uncluttered and allow for comparatively large symbol sizes. They visualize data sets well which are not proportional to region sizes. The linear ordering of the symbols along the necklace facilitates an easy comparison of symbol sizes. One map can contain several nested or disjoint necklaces to visualize clustered data. The advantages of necklace maps come at a price: the association between a symbol and its region is weaker than with other types of maps. Interactivity can help to strengthen this association if necessary. We present an automated approach to generate necklace maps which allows the user to interactively control the final symbol placement. We validate our approach with experiments using various data sets and maps. 2010 geographic InfoVis Visualization and Computer Graphics, IEEE Transactions on geographic visualization Speckmann, B. Verbeek, K. automated cartography Necklace Maps proportional symbol maps infovis10--191 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Rethinking Map Legends with Visualization. This design paper presents new guidance for creating map legends in a dynamic environment. Our contribution is a set ofguidelines for legend design in a visualization context and a series of illustrative themes through which they may be expressed. Theseare demonstrated in an applications context through interactive software prototypes. The guidelines are derived from cartographicliterature and in liaison with EDINA who provide digital mapping services for UK tertiary education. They enhance approaches tolegend design that have evolved for static media with visualization by considering: selection, layout, symbols, position, dynamismand design and process. Broad visualization legend themes include: The Ground Truth Legend, The Legend as Statistical Graphicand The Map is the Legend. Together, these concepts enable us to augment legends with dynamic properties that address specificneeds, rethink their nature and role and contribute to a wider re-evaluation of maps as artifacts of usage rather than statements offact. EDINA has acquired funding to enhance their clients with visualization legends that use these concepts as a consequence ofthis work. The guidance applies to the design of a wide range of legends and keys used in cartography and information visualization. 2010 visualization evaluation education design InfoVis Visualization and Computer Graphics, IEEE Transactions on Dykes, J. Slingsby, A. Wood, J. cartography digimap service legend online web mapping infovis10--193 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on SignalLens: Focus+Context Applied to Electronic Time Series. Electronic test and measurement systems are becoming increasingly sophisticated in order to match the increased complexity and ultra-high speed of the devices under test. A key feature in many such instruments is a vastly increased capacity for storage of digital signals. Storage of 109 time points or more is now possible. At the same time, the typical screens on such measurement devices are relatively small. Therefore, these instruments can only render an extremely small fraction of the complete signal at any time. SignalLens uses a Focus+Context approach to provide a means of navigating to and inspecting low-level signal details in the context of the entire signal trace. This approach provides a compact visualization suitable for embedding into the small displays typically provided by electronic measurement instruments. We further augment this display with computed tracks which display time-aligned computed properties of the signal. By combining and filtering these computed tracks it is possible to easily and quickly find computationally detected features in the data which are often obscured by the visual compression required to render the large data sets on a small screen. Further, these tracks can be viewed in the context of the entire signal trace as well as visible high-level signal features. Several examples using real-world electronic measurement data are presented, which demonstrate typical use cases and the effectiveness of the design. 2010 time series Kincaid, R. InfoVis Visualization and Computer Graphics, IEEE Transactions on focus+context focus+context electronic signal lens signal processing test and measurement infovis10--137 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on MulteeSum: A Tool for Comparative Spatial and Temporal Gene Expression Data. Cells in an organism share the same genetic information in their DNA, but have very different forms and behavior because of the selective expression of subsets of their genes. The widely used approach of measuring gene expression over time from a tissue sample using techniques such as microarrays or sequencing do not provide information about the spatial position with in the tissue where these genes are expressed. In contrast, we are working with biologists who use techniques that measure gene expression in every individual cell of entire fruitfly embryos over an hour of their development, and do so for multiple closely-related subspecies of Drosophila. These scientists are faced with the challenge of integrating temporal gene expression data with the spatial location of cells and, moreover, comparing this data across multiple related species. We have worked with these biologists over the past two years to develop MulteeSum, a visualization system that supports inspection and curation of data sets showing gene expression over time, in conjunction with the spatial location of the cells where the genes are expressed - it is the first tool to support comparisons across multiple such data sets. MulteeSum is part of a general and flexible framework we developed with our collaborators that is built around multiple summaries for each cell, allowing the biologists to explore the results of computations that mix spatial information, gene expression measurements over time, and data from multiple related species or organisms. We justify our design decisions based on specific descriptions of the analysis needs of our collaborators, and provide anecdotal evidence of the efficacy of MulteeSum through a series of case studies. 2010 Munzner, T. InfoVis Visualization and Computer Graphics, IEEE Transactions on spatial data Meyer, M. Pfister, H. DePace, A. gene expression temporal data infovis10--163 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Gremlin: An Interactive Visualization Model for Analyzing Genomic Rearrangements. In this work we present, apply, and evaluate a novel, interactive visualization model for comparative analysis of structural variants and rearrangements in human and cancer genomes, with emphasis on data integration and uncertainty visualization. To support both global trend analysis and local feature detection, this model enables explorations continuously scaled from the high-level, complete genome perspective, down to the low-level, structural rearrangement view, while preserving global context at all times. We have implemented these techniques in Gremlin, a genomic rearrangement explorer with multi-scale, linked interactions, which we apply to four human cancer genome data sets for evaluation. Using an insight-based evaluation methodology, we compare Gremlin to Circos, the state-of-the-art in genomic rearrangement visualization, through a small user study with computational biologists working in rearrangement analysis. Results from user study evaluations demonstrate that this visualization model enables more total insights, more insights per minute, and more complex insights than the current state-of-the-art for visual analysis and exploration of genome rearrangements. 2010 user study insight uncertainty evaluation bioinformatics InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization O'Brien, T.M. Ritz, A.M. Raphael, B.J. Laidlaw, D.H. insight-based evaluation infovis10--162 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Graphical Perception of Multiple Time Series. Line graphs have been the visualization of choice for temporal data ever since the days of William Playfair (1759-1823), but realistic temporal analysis tasks often include multiple simultaneous time series. In this work, we explore user performance for comparison, slope, and discrimination tasks for different line graph techniques involving multiple time series. Our results show that techniques that create separate charts for each time series--such as small multiples and horizon graphs--are generally more efficient for comparisons across time series with a large visual span. On the other hand, shared-space techniques--like standard line graphs--are typically more efficient for comparisons over smaller visual spans where the impact of overlap and clutter is reduced. 2010 graph time series evaluation perception Elmqvist, N. small multiples InfoVis Visualization and Computer Graphics, IEEE Transactions on small multiples McDonnel, B. Javed, W. braided graphs design guidelines horizon graphs line graphs stacked graphs infovis10--209 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Uncovering Strengths and Weaknesses of Radial Visualizations---an Empirical Approach. Radial visualizations play an important role in the information visualization community. But the decision to choose a radial coordinate system is rather based on intuition than on scientific foundations. The empirical approach presented in this paper aims at uncovering strengths and weaknesses of radial visualizations by comparing them to equivalent ones in Cartesian coordinate systems. We identified memorizing positions of visual elements as a generic task when working with visualizations. A first study with 674 participants provides a broad data spectrum for exploring differences between the two visualization types. A second, complementing study with fewer participants focuses on further questions raised by the first study. Our findings document that Cartesian visualizations tend to outperform their radial counterparts especially with respect to answer times. Nonetheless, radial visualization seem to be more appropriate for focusing on a particular data dimension. 2010 document radial InfoVis Visualization and Computer Graphics, IEEE Transactions on user study radial visualization Diehl, S. Beck, F. Burch, M. visual memory infovis10--164 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on How Information Visualization Novices Construct Visualizations. It remains challenging for information visualization novices to rapidly construct visualizations during exploratory data analysis. We conducted an exploratory laboratory study in which information visualization novices explored fictitious sales data by communicating visualization specifications to a human mediator, who rapidly constructed the visualizations using commercial visualization software. We found that three activities were central to the iterative visualization construction process: data attribute selection, visual template selection, and visual mapping specification. The major barriers faced by the participants were translating questions into data attributes, designing visual mappings, and interpreting the visualizations. Partial specification was common, and the participants used simple heuristics and preferred visualizations they were already familiar with, such as bar, line and pie charts. We derived abstract models from our observations that describe barriers in the data exploration process and uncovered how information visualization novices think about visualization specifications. Our findings support the need for tools that suggest potential visualizations and support iterative refinement, that provide explanations and help with learning, and that are tightly integrated into tool support for the overall visual analytics process. visual analytics visual analytics 2010 visualization Tory, M. InfoVis Visualization and Computer Graphics, IEEE Transactions on Storey, M. Grammel, L. empirical study novices visual mapping visualization construction infovis10--149 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on eSeeTrack - Visualizing Sequential Fixation Patterns. We introduce eSeeTrack, an eye-tracking visualization prototype that facilitates exploration and comparison of sequential gaze orderings in a static or a dynamic scene. It extends current eye-tracking data visualizations by extracting patterns of sequential gaze orderings, displaying these patterns in a way that does not depend on the number of fixations on a scene, and enabling users to compare patterns from two or more sets of eye-gaze data. Extracting such patterns was very difficult with previous visualization techniques. eSeeTrack combines a timeline and a tree-structured visual representation to embody three aspects of eye-tracking data that users are interested in: duration, frequency and orderings of fixations. We demonstrate the usefulness of eSeeTrack via two case studies on surgical simulation and retail store chain data. We found that eSeeTrack allows ordering of fixations to be rapidly queried, explored and compared. Furthermore, our tool provides an effective and efficient mechanism to determine pattern outliers. This approach can be effective for behavior analysis in a variety of domains that are described at the end of this paper. 2010 Tory, M. InfoVis Visualization and Computer Graphics, IEEE Transactions on timeline Swindells, C. Tsang, H.Y. eye-tracking fixation pattern tree-structured visualization infovis10--150 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Evaluating the impact of task demands and block resolution on the effectiveness of pixel-based visualization. Pixel-based visualization is a popular method of conveying large amounts of numerical data graphically. Application scenarios include business and finance, bioinformatics and remote sensing. In this work, we examined how the usability of such visual representations varied across different tasks and block resolutions. The main stimuli consisted of temporal pixel-based visualization with a white-red color map, simulating monthly temperature variation over a six-year period. In the first study, we included 5 separate tasks to exert different perceptual loads. We found that performance varied considerably as a function of task, ranging from 75% correct in low-load tasks to below 40% in high-load tasks. There was a small but consistent effect of resolution, with the uniform patch improving performance by around 6% relative to higher block resolution. In the second user study, we focused on a high-load task for evaluating month-to-month changes across different regions of the temperature range. We tested both CIE L*u*v* and RGB color spaces. We found that the nature of the change-evaluation errors related directly to the distance between the compared regions in the mapped color space. We were able to reduce such errors by using multiple color bands for the same data range. In a final study, we examined more fully the influence of block resolution on performance, and found block resolution had a limited impact on the effectiveness of pixel-based visualization. 2010 user study business evaluation usability pixel evaluation bioinformatics InfoVis color Visualization and Computer Graphics, IEEE Transactions on user study Chen, M. Borgo, R. Proctor, K. Janicke, H. Murray, T. Thornton, I.M. pixel-based visualization change detection visual search infovis10--161 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Graphical inference for infovis. How do we know if what we see is really there? When visualizing data, how do we avoid falling into the trap of apophenia where we see patterns in random noise? Traditionally, infovis has been concerned with discovering new relationships, and statistics with preventing spurious relationships from being reported. We pull these opposing poles closer with two new techniques for rigorous statistical inference of visual discoveries. The "Rorschach" helps the analyst calibrate their understanding of uncertainty and "line-up" provides a protocol for assessing the significance of visual discoveries, protecting against the discovery of spurious structure. 2010 uncertainty statistics InfoVis Visualization and Computer Graphics, IEEE Transactions on Wickham, H. Cook, D. Hofmann, H. Buja, A. statistics data plot null hypotheses permutation tests visual testing infovis10--176 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Matching Visual Saliency to Confidence in Plots of Uncertain Data. Conveying data uncertainty in visualizations is crucial for preventing viewers from drawing conclusions based on untrustworthy data points. This paper proposes a methodology for efficiently generating density plots of uncertain multivariate data sets that draws viewers to preattentively identify values of high certainty while not calling attention to uncertain values. We demonstrate how to augment scatter plots and parallel coordinates plots to incorporate statistically modeled uncertainty and show how to integrate them with existing multivariate analysis techniques, including outlier detection and interactive brushing. Computing high quality density plots can be expensive for large data sets, so we also describe a probabilistic plotting technique that summarizes the data without requiring explicit density plot computation. These techniques have been useful for identifying brain tumors in multivariate magnetic resonance spectroscopy data and we describe how to extend them to visualize ensemble data sets. 2010 uncertainty parallel coordinates multivariate data brushing parallel coordinates InfoVis Visualization and Computer Graphics, IEEE Transactions on brushing Feng, D. Kwock, L. Lee, Y. Taylor, R.M. uncertainty visualization scatterplot infovis10--186 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Perceptual Guidelines for Creating Rectangular Treemaps. Treemaps are space-filling visualizations that make efficient use of limited display space to depict large amounts of hierarchical data. Creating perceptually effective treemaps requires carefully managing a number of design parameters including the aspect ratio and luminance of rectangles. Moreover, treemaps encode values using area, which has been found to be less accurate than judgments of other visual encodings, such as length. We conduct a series of controlled experiments aimed at producing a set of design guidelines for creating effective rectangular treemaps. We find no evidence that luminance affects area judgments, but observe that aspect ratio does have an effect. Specifically, we find that the accuracy of area comparisons suffers when the compared rectangles have extreme aspect ratios or when both are squares. Contrary to common assumptions, the optimal distribution of rectangle aspect ratios within a treemap should include non-squares, but should avoid extremes. We then compare treemaps with hierarchical bar chart displays to identify the data densities at which length-encoded bar charts become less effective than area-encoded treemaps. We report the transition points at which treemaps exhibit judgment accuracy on par with bar charts for both leaf and non-leaf tree nodes. We also find that even at relatively low data densities treemaps result in faster comparisons than bar charts. Based on these results, we present a set of guidelines for the effective use of treemaps and suggest alternate approaches for treemap layout. 2010 visualization Heer, J. Agrawala, M. InfoVis Visualization and Computer Graphics, IEEE Transactions on treemap treemap Kong, N. experiment graphical perception Mechanical Turk rectangular area visual encoding infovis10--177 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Mental Models, Visual Reasoning and Interaction in Information Visualization: A Top-down Perspective. Although previous research has suggested that examining the interplay between internal and external representations can benefit our understanding of the role of information visualization (InfoVis) in human cognitive activities, there has been little work detailing the nature of internal representations, the relationship between internal and external representations and how interaction is related to these representations. In this paper, we identify and illustrate a specific kind of internal representation, mental models, and outline the high-level relationships between mental models and external visualizations. We present a top-down perspective of reasoning as model construction and simulation, and discuss the role of visualization in model based reasoning. From this perspective, interaction can be understood as active modeling for three primary purposes: external anchoring, information foraging, and cognitive offloading. Finally we discuss the implications of our approach for design, evaluation and theory development. interaction 2010 Liu, Z. evaluation interaction Stasko, J. theory information visualization InfoVis Visualization and Computer Graphics, IEEE Transactions on theory distributed cognition mental model model-based reasoning infovis10--174 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Laws of Attraction: From Perceptual Forces to Conceptual Similarity. Many of the pressing questions in information visualization deal with how exactly a user reads a collection of visual marks as information about relationships between entities. Previous research has suggested that people see parts of a visualization as objects, and may metaphorically interpret apparent physical relationships between these objects as suggestive of data relationships. We explored this hypothesis in detail in a series of user experiments. Inspired by the concept of implied dynamics in psychology, we first studied whether perceived gravity acting on a mark in a scatterplot can lead to errors in a participant's recall of the mark's position. The results of this study suggested that such position errors exist, but may be more strongly influenced by attraction between marks. We hypothesized that such apparent attraction may be influenced by elements used to suggest relationship between objects, such as connecting lines, grouping elements, and visual similarity. We further studied what visual elements are most likely to cause this attraction effect, and whether the elements that best predicted attraction errors were also those which suggested conceptual relationships most strongly. Our findings show a correlation between attraction errors and intuitions about relatedness, pointing towards a possible mechanism by which the perception of visual marks becomes an interpretation of data relationships. 2010 Ziemkiewicz, C. scatterplot perception Kosara, R. InfoVis Visualization and Computer Graphics, IEEE Transactions on visualization models perceptual cognition cognition theory laboratory study infovis10--184 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Pargnostics: Screen-Space Metrics for Parallel Coordinates. Interactive visualization requires the translation of data into a screen space of limited resolution. While currently ignored by most visualization models, this translation entails a loss of information and the introduction of a number of artifacts that can be useful, (e.g., aggregation, structures) or distracting (e.g., over-plotting, clutter) for the analysis. This phenomenon is observed in parallel coordinates, where overlapping lines between adjacent axes form distinct patterns, representing the relation between variables they connect. However, even for a small number of dimensions, the challenge is to effectively convey the relationships for all combinations of dimensions. The size of the dataset and a large number of dimensions only add to the complexity of this problem. To address these issues, we propose Pargnostics, parallel coordinates diagnostics, a model based on screen-space metrics that quantify the different visual structures. Pargnostics metrics are calculated for pairs of axes and take into account the resolution of the display as well as potential axis inversions. Metrics include the number of line crossings, crossing angles, convergence, overplotting, etc. To construct a visualization view, the user can pick from a ranked display showing pairs of coordinate axes and the structures between them, or examine all possible combinations of axes at once in a matrix display. Picking the best axes layout is an NP-complete problem in general, but we provide a way of automatically optimizing the display according to the user's preferences based on our metrics and model. 2010 parallel coordinates matrix metrics Kosara, R. metrics InfoVis Visualization and Computer Graphics, IEEE Transactions on parallel coordinates visualization models Dasgupta, A. display optimization infovis10--138 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Comparative Analysis of Multidimensional, Quantitative Data. When analyzing multidimensional, quantitative data, the comparison of two or more groups of dimensions is a common task. Typical sources of such data are experiments in biology, physics or engineering, which are conducted in different configurations and use replicates to ensure statistically significant results. One common way to analyze this data is to filter it using statistical methods and then run clustering algorithms to group similar values. The clustering results can be visualized using heat maps, which show differences between groups as changes in color. However, in cases where groups of dimensions have an a priori meaning, it is not desirable to cluster all dimensions combined, since a clustering algorithm can fragment continuous blocks of records. Furthermore, identifying relevant elements in heat maps becomes more difficult as the number of dimensions increases. To aid in such situations, we have developed Matchmaker, a visualization technique that allows researchers to arbitrarily arrange and compare multiple groups of dimensions at the same time. We create separate groups of dimensions which can be clustered individually, and place them in an arrangement of heat maps reminiscent of parallel coordinates. To identify relations, we render bundled curves and ribbons between related records in different groups. We then allow interactive drill-downs using enlarged detail views of the data, which enable in-depth comparisons of clusters between groups. To reduce visual clutter, we minimize crossings between the views. This paper concludes with two case studies. The first demonstrates the value of our technique for the comparison of clustering algorithms. In the second, biologists use our system to investigate why certain strains of mice develop liver disease while others remain healthy, informally showing the efficacy of our system when analyzing multidimensional data containing distinct groups of dimensions. 2010 cluster clustering parallel coordinates filter InfoVis color Visualization and Computer Graphics, IEEE Transactions on Lex, A. Streit, M. Partl, C. Kashofer, K. Schmalstieg, D. bioinformatics visualization cluster comparison multidimensional data infovis10--130 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on An Extension of Wilkinson's Algorithm for Positioning Tick Labels on Axes. The non-data components of a visualization, such as axes and legends, can often be just as important as the data itself. They provide contextual information essential to interpreting the data. In this paper, we describe an automated system for choosing positions and labels for axis tick marks. Our system extends Wilkinson's optimization-based labeling approach to create a more robust, full-featured axis labeler. We define an expanded space of axis labelings by automatically generating additional nice numbers as needed and by permitting the extreme labels to occur inside the data range. These changes provide flexibility in problematic cases, without degrading quality elsewhere. We also propose an additional optimization criterion, legibility, which allows us to simultaneously optimize over label formatting, font size, and orientation. To solve this revised optimization problem, we describe the optimization function and an efficient search algorithm. Finally, we compare our method to previous work using both quantitative and qualitative metrics. This paper is a good example of how ideas from automated graphic design can be applied to information visualization. 2010 metrics Hanrahan, P. InfoVis Visualization and Computer Graphics, IEEE Transactions on Talbot, J. Lin, S. axis labeling nice numbers infovis10--197 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Stacking Graphic Elements to Avoid Over-Plotting. An ongoing challenge for information visualization is how to deal with over-plotting forced by ties or the relatively limited visual field of display devices. A popular solution is to represent local data density with area (bubble plots, treemaps), color(heatmaps), or aggregation (histograms, kernel densities, pixel displays). All of these methods have at least one of three deficiencies:1) magnitude judgments are biased because area and color have convex downward perceptual functions, 2) area, hue, and brightnesshave relatively restricted ranges of perceptual intensity compared to length representations, and/or 3) it is difficult to brush or link toindividual cases when viewing aggregations. In this paper, we introduce a new technique for visualizing and interacting with datasets that preserves density information by stacking overlapping cases. The overlapping data can be points or lines or other geometric elements, depending on the type of plot. We show real-dataset applications of this stacking paradigm and compare them to other techniques that deal with over-plotting in high-dimensional displays. 2010 pixel multidimensional data InfoVis color Visualization and Computer Graphics, IEEE Transactions on Wilkinson, L. Anand, A. Dang, T.N. density-based visualization parallel coordinate plots dot plots infovis10--216 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Visualization of Diversity in Large Multivariate Data Sets. Understanding the diversity of a set of multivariate objects is an important problem in many domains, including ecology, college admissions, investing, machine learning, and others. However, to date, very little work has been done to help users achieve this kind of understanding. Visual representation is especially appealing for this task because it offers the potential to allow users to efficiently observe the objects of interest in a direct and holistic way. Thus, in this paper, we attempt to formalize the problem of visualizing the diversity of a large (more than 1000 objects), multivariate (more than 5 attributes) data set as one worth deeper investigation by the information visualization community. In doing so, we contribute a precise definition of diversity, a set of requirements for diversity visualizations based on this definition, and a formal user study design intended to evaluate the capacity of a visual representation for communicating diversity information. Our primary contribution, however, is a visual representation, called the Diversity Map, for visualizing diversity. An evaluation of the Diversity Map using our study design shows that users can judge elements of diversity consistently and as or more accurately than when using the only other representation specifically designed to visualize diversity. 2010 user study evaluation machine learning multivariate data evaluation information visualization InfoVis Visualization and Computer Graphics, IEEE Transactions on Zhang, E. categorical data Pham, T. Hess, R. Ju, C. Metoyer, R. diversity infovis10--185 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on PedVis: A Structured, Space-Efficient Technique for Pedigree Visualization. Public genealogical databases are becoming increasingly populated with historical data and records of the current population's ancestors. As this increasing amount of available information is used to link individuals to their ancestors, the resulting trees become deeper and more dense, which justifies the need for using organized, space-efficient layouts to display the data. Existing layouts are often only able to show a small subset of the data at a time. As a result, it is easy to become lost when navigating through the data or to lose sight of the overall tree structure. On the contrary, leaving space for unknown ancestors allows one to better understand the tree's structure, but leaving this space becomes expensive and allows fewer generations to be displayed at a time. In this work, we propose that the H-tree based layout be used in genealogical software to display ancestral trees. We will show that this layout presents an increase in the number of displayable generations, provides a nicely arranged, symmetrical, intuitive and organized fractal structure, increases the user's ability to understand and navigate through the data, and accounts for the visualization requirements necessary for displaying such trees. Finally, user-study results indicate potential for user acceptance of the new layout. 2010 InfoVis Visualization and Computer Graphics, IEEE Transactions on Tuttle, C. Nonato, L.G. Silva, C. genealogy H-Tree pedigree infovis10--159 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on GeneaQuilts: A System for Exploring Large Genealogies. GeneaQuilts is a new visualization technique for representing large genealogies of up to several thousand individuals. The visualization takes the form of a diagonally-filled matrix, where rows are individuals and columns are nuclear families. After identifying the major tasks performed in genealogical research and the limits of current software, we present an interactive genealogy exploration system based on GeneaQuilts. The system includes an overview, a timeline, search and filtering components, and a new interaction technique called Bring & Slide that allows fluid navigation in very large genealogies. We report on preliminary feedback from domain experts and show how our system supports a number of their tasks. interaction 2010 Fekete, J.-D. overview interaction matrix navigation InfoVis Visualization and Computer Graphics, IEEE Transactions on Dragicevic, P. Bezerianos, A. Bae, J. Watson, B. genealogy visualization infovis10--217 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Visualization of Graph Products. Graphs are a versatile structure and abstraction for binary relationships between objects. To gain insight into such relationships, their corresponding graph can be visualized. In the past, many classes of graphs have been defined, e.g. trees, planar graphs, directed acyclic graphs, and visualization algorithms were proposed for these classes. Although many graphs may only be classified as "general" graphs, they can contain substructures that belong to a certain class. Archambault proposed the TopoLayout framework: rather than draw any arbitrary graph using one method, split the graph into components that are homogeneous with respect to one graph class and then draw each component with an algorithm best suited for this class. Graph products constitute a class that arises frequently in graph theory, but for which no visualization algorithm has been proposed until now. In this paper, we present an algorithm for drawing graph products and the aesthetic criterion graph product's drawings are subject to. We show that the popular High-Dimensional Embedder approach applied to cartesian products already respects this aestetic criterion, but has disadvantages. We also present how our method is integrated as a new component into the TopoLayout framework. Our implementation is used for further research of graph products in a biological context. 2010 insight graph Scheuermann, G. theory InfoVis Visualization and Computer Graphics, IEEE Transactions on Heine, C. Stadler, P.F. graph drawing Janicke, S. Hellmuth, M. TopoLayout graph products infovis10--210 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Untangling Euler Diagrams. In many common data analysis scenarios the data elements are logically grouped into sets. Venn and Euler style diagrams are a common visual representation of such set membership where the data elements are represented by labels or glyphs and sets are indicated by boundaries surrounding their members. Generating such diagrams automatically such that set regions do not intersect unless the corresponding sets have a non-empty intersection is a difficult problem. Further, it may be impossible in some cases if regions are required to be continuous and convex. Several approaches exist to draw such set regions using more complex shapes, however, the resulting diagrams can be difficult to interpret. In this paper we present two novel approaches for simplifying a complex collection of intersecting sets into a strict hierarchy that can be more easily automatically arranged and drawn (Figure 1). In the first approach, we use compact rectangular shapes for drawing each set, attempting to improve the readability of the set intersections. In the second approach, we avoid drawing intersecting set regions by duplicating elements belonging to multiple sets. We compared both of our techniques to the traditional non-convex region technique using five readability tasks. Our results show that the compact rectangular shapes technique was often preferred by experimental subjects even though the use of duplications dramatically improves the accuracy and performance time for most of our tasks. In addition to general set representation our techniques are also applicable to visualization of networks with intersecting clusters of nodes. 2010 information visualization hierarchy InfoVis Visualization and Computer Graphics, IEEE Transactions on Henry Riche, N. Dwyer, T. Euler diagrams graph visualization set visualization infovis10--205 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on The FlowVizMenu and Parallel Scatterplot Matrix: Hybrid Multidimensional Visualizations for Network Exploration. A standard approach for visualizing multivariate networks is to use one or more multidimensional views (for example, scatterplots) for selecting nodes by various metrics, possibly coordinated with a node-link view of the network. In this paper, we present three novel approaches for achieving a tighter integration of these views through hybrid techniques for multidimensional visualization, graph selection and layout. First, we present the FlowVizMenu, a radial menu containing a scatterplot that can be popped up transiently and manipulated with rapid, fluid gestures to select and modify the axes of its scatterplot. Second, the FlowVizMenu can be used to steer an attribute-driven layout of the network, causing certain nodes of a node-link diagram to move toward their corresponding positions in a scatterplot while others can be positioned manually or by force-directed layout. Third, we describe a novel hybrid approach that combines a scatterplot matrix (SPLOM) and parallel coordinates called the Parallel Scatterplot Matrix (P-SPLOM), which can be used to visualize and select features within the network. We also describe a novel arrangement of scatterplots called the Scatterplot Staircase (SPLOS) that requires less space than a traditional scatterplot matrix. Initial user feedback is reported. 2010 network graph scatterplot parallel coordinates matrix metrics radial parallel coordinates InfoVis Visualization and Computer Graphics, IEEE Transactions on scatterplot matrix Chiricota, Y. McGuffin, M.J. network layout Jurisica, I. interactive graph drawing Viau, C. attribute-driven layout radial menu infovis10--183 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on OpinionSeer: Interactive Visualization of Hotel Customer Feedback. The rapid development of Web technology has resulted in an increasing number of hotel customers sharing their opinions on the hotel services. Effective visual analysis of online customer opinions is needed, as it has a significant impact on building a successful business. In this paper, we present OpinionSeer, an interactive visualization system that could visually analyze a large collection of online hotel customer reviews. The system is built on a new visualization-centric opinion mining technique that considers uncertainty for faithfully modeling and analyzing customer opinions. A new visual representation is developed to convey customer opinions by augmenting well-established scatterplots and radial visualization. To provide multiple-level exploration, we introduce subjective logic to handle and organize subjective opinions with degrees of uncertainty. Several case studies illustrate the effectiveness and usefulness of OpinionSeer on analyzing relationships among multiple data dimensions and comparing opinions of different groups. Aside from data on hotel customer feedback, OpinionSeer could also be applied to visually analyze customer opinions on other products or services. 2010 business uncertainty Liu, S. Wei, F. radial InfoVis Visualization and Computer Graphics, IEEE Transactions on Qu, H. uncertainty visualization radial visualization Zhou, H. Cui, W. Wu, Y. Au, N. opinion visualization infovis10--206 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on The Streams of Our Lives: Visualizing Listening Histories in Context. The choices we take when listening to music are expressions of our personal taste and character. Storing and accessing our listening histories is trivial due to services like Last.fm, but learning from them and understanding them is not. Existing solutions operate at a very abstract level and only produce statistics. By applying techniques from information visualization to this problem, we were able to provide average people with a detailed and powerful tool for accessing their own musical past. LastHistory is an interactive visualization for displaying music listening histories, along with contextual information from personal photos and calendar entries. Its two main user tasks are (1) analysis, with an emphasis on temporal patterns and hypotheses related to musical genre and sequences, and (2) reminiscing, where listening histories and context represent part of one's past. In this design study paper we give an overview of the field of music listening histories and explain their unique characteristics as a type of personal data. We then describe the design rationale, data and view transformations of LastHistory and present the results from both a laband a large-scale online study. We also put listening histories in contrast to other lifelogging data. The resonant and enthusiastic feedback that we received from average users shows a need for making their personal data accessible. We hope to stimulate such developments through this research. 2010 overview statistics InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization music design study listening history design study Baur, D. Seiffert, F. Sedlmair, M. Boring, S. calendars lifelogging photos timeline infovis10--129 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on A Visual Backchannel for Large-Scale Events. We introduce the concept of a Visual Backchannel as a novel way of following and exploring online conversations about large-scale events. Microblogging communities, such as Twitter, are increasingly used as digital backchannels for timely exchange of brief comments and impressions during political speeches, sport competitions, natural disasters, and other large events. Currently, shared updates are typically displayed in the form of a simple list, making it difficult to get an overview of the fast-paced discussions as it happens in the moment and how it evolves over time. In contrast, our Visual Backchannel design provides an evolving, interactive, and multi-faceted visual overview of large-scale ongoing conversations on Twitter. To visualize a continuously updating information stream, we include visual saliency for what is happening now and what has just happened, set in the context of the evolving conversation. As part of a fully web-based coordinated-view system we introduce Topic Streams, a temporally adjustable stacked graph visualizing topics over time, a People Spiral representing participants and their activity, and an Image Cloud encoding the popularity of event photos by size. Together with a post listing, these mutually linked views support cross-filtering along topics, participants, and time ranges. We discuss our design considerations, in particular with respect to evolving visualizations of dynamically changing data. Initial feedback indicates significant interest and suggests several unanticipated uses. 2010 graph overview information retrieval information visualization multiple views InfoVis Visualization and Computer Graphics, IEEE Transactions on Carpendale, S. World Wide Web Williamson, C. Dork, M. Gruen, D. backchannel events microblogging infovis10--179 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Narrative Visualization: Telling Stories with Data. Data visualization is regularly promoted for its ability to reveal stories within data, yet these "data stories" differ in important ways from traditional forms of storytelling. Storytellers, especially online journalists, have increasingly been integrating visualizations into their narratives, in some cases allowing the visualization to function in place of a written story. In this paper, we systematically review the design space of this emerging class of visualizations. Drawing on case studies from news media to visualization research, we identify distinct genres of narrative visualization. We characterize these design differences, together with interactivity and messaging, in terms of the balance between the narrative flow intended by the author (imposed by graphical elements and the interface) and story discovery on the part of the reader (often through interactive exploration). Our framework suggests design strategies for narrative visualization, including promising under-explored approaches to journalistic storytelling and educational media. 2010 Heer, J. InfoVis Visualization and Computer Graphics, IEEE Transactions on social data analysis case study Segel, E. narrative visualization design methods journalism storytelling infovis10--144 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on Declarative Language Design for Interactive Visualization. We investigate the design of declarative, domain-specific languages for constructing interactive visualizations. By separating specification from execution, declarative languages can simplify development, enable unobtrusive optimization, and support retargeting across platforms. We describe the design of the Protovis specification language and its implementation within an object-oriented, statically-typed programming language (Java). We demonstrate how to support rich visualizations without requiring a toolkit-specific data model and extend Protovis to enable declarative specification of animated transitions. To support cross-platform deployment, we introduce rendering and event-handling infrastructures decoupled from the runtime platform, letting designers retarget visualization specifications (e.g., from desktop to mobile phone) with reduced effort. We also explore optimizations such as runtime compilation of visualization specifications, parallelized execution, and hardware-accelerated rendering. We present benchmark studies measuring the performance gains provided by these optimizations and compare performance to existing Java-based visualization tools, demonstrating scalability improvements exceeding an order of magnitude. 2010 information visualization hardware Heer, J. toolkit user interface InfoVis Visualization and Computer Graphics, IEEE Transactions on Bostock, M. toolkit declarative languages domain specific languages optimization infovis10--222 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on WebCharts: Extending Applications with Web-Authored, Embeddable Visualizations. In order to use new visualizations, most toolkits require application developers to rebuild their applications and distribute new versions to users. The WebCharts Framework take a different approach by hosting Javascript from within an application and providing a standard data and events interchange.. In this way, applications can be extended dynamically, with a wide variety of visualizations. We discuss the benefits of this architectural approach, contrast it to existing techniques, and give a variety of examples and extensions of the basic system. 2010 Fisher, D. InfoVis Visualization and Computer Graphics, IEEE Transactions on Fernandez, R. Drucker, S.M. Ruble, S. visualization systems data transformation and representation toolkit design infovis10--126 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on behaviorism: A Framework for Dynamic Data Visualization. While a number of information visualization software frameworks exist, creating new visualizations, especially those that involve novel visualization metaphors, interaction techniques, data analysis strategies, and specialized rendering algorithms, is still often a difficult process. To facilitate the creation of novel visualizations we present a new software framework, behaviorism, which provides a wide range of flexibility when working with dynamic information on visual, temporal, and ontological levels, but at the same time providing appropriate abstractions which allow developers to create prototypes quickly which can then easily be turned into robust systems. The core of the framework is a set of three interconnected graphs, each with associated operators: a scene graph for high-performance 3D rendering, a data graph for different layers of semantically linked heterogeneous data, and a timing graph for sophisticated control of scheduling, interaction, and animation. In particular, the timing graph provides a unified system to add behaviors to both data and visual elements, as well as to the behaviors themselves. To evaluate the framework we look briefly at three different projects all of which required novel visualizations in different domains, and all of which worked with dynamic data in different ways: an interactive ecological simulation, an information art installation, and an information visualization technique. interaction 2010 graph animation InfoVis Visualization and Computer Graphics, IEEE Transactions on Forbes, A. Hollerer, T. Legrady, G. animation streaming data time-varying data visual design visualization system and toolkit design infovis10--154 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on FacetAtlas: Multifaceted Visualization for Rich Text Corpora. Documents in rich text corpora usually contain multiple facets of information. For example, an article about a specific disease often consists of different facets such as symptom, treatment, cause, diagnosis, prognosis, and prevention. Thus, documents may have different relations based on different facets. Powerful search tools have been developed to help users locate lists of individual documents that are most related to specific keywords. However, there is a lack of effective analysis tools that reveal the multifaceted relations of documents within or cross the document clusters. In this paper, we present FacetAtlas, a multifaceted visualization technique for visually analyzing rich text corpora. FacetAtlas combines search technology with advanced visual analytical tools to convey both global and local patterns simultaneously. We describe several unique aspects of FacetAtlas, including (1) node cliques and multifaceted edges, (2) an optimized density map, and (3) automated opacity pattern enhancement for highlighting visual patterns, (4) interactive context switch between facets. In addition, we demonstrate the power of FacetAtlas through a case study that targets patient education in the health care domain. Our evaluation shows the benefits of this work, especially in support of complex multifaceted data analysis. 2010 document text evaluation case study Liu, S. text visualization education Gotz, D. InfoVis Visualization and Computer Graphics, IEEE Transactions on Qu, H. Cao, N. Sun, J. Lin, Y.-R. multi-relational graph multifaceted visualization search ui infovis10--194 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on SparkClouds: Visualizing Trends in Tag Clouds. Tag clouds have proliferated over the web over the last decade. They provide a visual summary of a collection of texts by visually depicting the tag frequency by font size. In use, tag clouds can evolve as the associated data source changes over time. Interesting discussions around tag clouds often include a series of tag clouds and consider how they evolve over time. However, since tag clouds do not explicitly represent trends or support comparisons, the cognitive demands placed on the person for perceiving trends in multiple tag clouds are high. In this paper, we introduce SparkClouds, which integrate sparklines into a tag cloud to convey trends between multiple tag clouds. We present results from a controlled study that compares SparkClouds with two traditional trend visualizations-multiple line graphs and stacked bar charts-as well as Parallel Tag Clouds. Results show that SparkClouds' ability to show trends compares favourably to the alternative visualizations. 2010 Lee, B. evaluation InfoVis Visualization and Computer Graphics, IEEE Transactions on Carpendale, S. Henry Riche, N. Karlson, A.K. tag cloud multiple line graphs stacked bar charts trend visualization infovis10--175 10/27/2010 Visualization and Computer Graphics, IEEE Transactions on ManiWordle: Providing Flexible Control over Wordle. Among the multifarious tag-clouding techniques, Wordle stands out to the community by providing an aesthetic layout, eliciting the emergence of the participatory culture and usage of tag-clouding in the artistic creations. In this paper, we introduce ManiWordle, a Wordle-based visualization tool that revamps interactions with the layout by supporting custom manipulations. ManiWordle allows people to manipulate typography, color, and composition not only for the layout as a whole, but also for the individual words, enabling them to have better control over the layout result. We first describe our design rationale along with the interaction techniques for tweaking the layout. We then present the results both from the preliminary usability study and from the comparative study between ManiWordle and Wordle. The results suggest that ManiWordle provides higher user satisfaction and an efficient method of creating the desired "art work," harnessing the power behind the ever-increasing popularity of Wordle. interaction 2010 Lee, B. usability InfoVis color direct manipulation Seo, J. Visualization and Computer Graphics, IEEE Transactions on user study interaction design Kim, B. Koh, K. flexibilty-usability tradeoff participatory visualization tag cloud infovis11--255 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Visualization Rhetoric: Framing Effects in Narrative Visualization. Narrative visualizations combine conventions of communicative and exploratory information visualization to convey an intended story. We demonstrate visualization rhetoric as an analytical framework for understanding how design techniques that prioritize particular interpretations in visualizations that "tell a story" can significantly affect end-user interpretation. We draw a parallel between narrative visualization interpretation and evidence from framing studies in political messaging, decision-making, and literary studies. Devices for understanding the rhetorical nature of narrative information visualizations are presented, informed by the rigorous application of concepts from critical theory, semiotics, journalism, and political theory. We draw attention to how design tactics represent additions or omissions of information at various levels−the data, visual representation, textual annotations, and interactivity−and how visualizations denote and connote phenomena with reference to unstated viewing conventions and codes. Classes of rhetorical techniques identified via a systematic analysis of recent narrative visualizations are presented, and characterized according to their rhetorical contribution to the visualization. We describe how designers and researchers can benefit from the potentially positive aspects of visualization rhetoric in designing engaging, layered narrative visualizations and how our framework can shed light on how a visualization design prioritizes specific interpretations. We identify areas where future inquiry into visualization rhetoric can improve understanding of visualization interpretation. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization theory Hullman, J. Diakopoulos, N. rhetoric connotation denotation framing effects narrative visualization semiotics rhetoric semiotics infovis11--253 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Visualization of Parameter Space for Image Analysis. Image analysis algorithms are often highly parameterized and much human input is needed to optimize parameter settings. This incurs a time cost of up to several days. We analyze and characterize the conventional parameter optimization process for image analysis and formulate user requirements. With this as input, we propose a change in paradigm by optimizing parameters based on parameter sampling and interactive visual exploration. To save time and reduce memory load, users are only involved in the first step - initialization of sampling - and the last step - visual analysis of output. This helps users to more thoroughly explore the parameter space and produce higher quality results. We describe a custom sampling plug-in we developed for CellProfiler - a popular biomedical image analysis framework. Our main focus is the development of an interactive visualization technique that enables users to analyze the relationships between sampled input parameters and corresponding output. We implemented this in a prototype called Paramorama. It provides users with a visual overview of parameters and their sampled values. User-defined areas of interest are presented in a structured way that includes image-based output and a novel layout algorithm. To find optimal parameter settings, users can tag high- and low-quality results to refine their search. We include two case studies to illustrate the utility of this approach. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on overview information visualization image analysis algorithm design and analysis Pretorius, A.J. Bray, M. Carpenter, A.E. Ruddle, R.A. image analysis parameter space sampling visual analytics information processing sampling methods infovis11--251 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Visual Thinking In Action: Visualizations As Used On Whiteboards. While it is still most common for information visualization researchers to develop new visualizations from a data- or taskdriven perspective, there is growing interest in understanding the types of visualizations people create by themselves for personal use. As part of this recent direction, we have studied a large collection of whiteboards in a research institution, where people make active use of combinations of words, diagrams and various types of visuals to help them further their thought processes. Our goal is to arrive at a better understanding of the nature of visuals that are created spontaneously during brainstorming, thinking, communicating, and general problem solving on whiteboards. We use the qualitative approaches of open coding, interviewing, and affinity diagramming to explore the use of recognizable and novel visuals, and the interplay between visualization and diagrammatic elements with words, numbers and labels. We discuss the potential implications of our findings on information visualization design. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis encoding visualization Walny, J. Carpendale, S. Henry Riche, N. Venolia, G. Fawcett, P. diagrams observational study whiteboards infovis11--250 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on VisBricks: Multiform Visualization of Large, Inhomogeneous Data. Large volumes of real-world data often exhibit inhomogeneities: vertically in the form of correlated or independent dimensions and horizontally in the form of clustered or scattered data items. In essence, these inhomogeneities form the patterns in the data that researchers are trying to find and understand. Sophisticated statistical methods are available to reveal these patterns, however, the visualization of their outcomes is mostly still performed in a one-view-fits-all manner. In contrast, our novel visualization approach, VisBricks, acknowledges the inhomogeneity of the data and the need for different visualizations that suit the individual characteristics of the different data subsets. The overall visualization of the entire data set is patched together from smaller visualizations, there is one VisBrick for each cluster in each group of interdependent dimensions. Whereas the total impression of all VisBricks together gives a comprehensive high-level overview of the different groups of data, each VisBrick independently shows the details of the group of data it represents. State-of-the-art brushing and visual linking between all VisBricks furthermore allows the comparison of the groupings and the distribution of data items among them. In this paper, we introduce the VisBricks visualization concept, discuss its design rationale and implementation, and demonstrate its usefulness by applying it to a use case from the field of biomedicine. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization overview Streit, M. Lex, A. Schmalstieg, D. brushing Schulz, H. multiform visualization semantics cluster Partl, C. inhomogeneous data multiple coordinated views nonhomogeneous media infovis11--247 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on TreeNetViz: Revealing Patterns of Networks over Tree Structures. Network data often contain important attributes from various dimensions such as social affiliations and areas of expertise in a social network. If such attributes exhibit a tree structure, visualizing a compound graph consisting of tree and network structures becomes complicated. How to visually reveal patterns of a network over a tree has not been fully studied. In this paper, we propose a compound graph model, TreeNet, to support visualization and analysis of a network at multiple levels of aggregation over a tree. We also present a visualization design, TreeNetViz, to offer the multiscale and cross-scale exploration and interaction of a TreeNet graph. TreeNetViz uses a Radial, Space-Filling (RSF) visualization to represent the tree structure, a circle layout with novel optimization to show aggregated networks derived from TreeNet, and an edge bundling technique to reduce visual complexity. Our circular layout algorithm reduces both total edge-crossings and edge length and also considers hierarchical structure constraints and edge weight in a TreeNet graph. These experiments illustrate that the algorithm can reduce visual cluttering in TreeNet graphs. Our case study also shows that TreeNetViz has the potential to support the analysis of a compound graph by revealing multiscale and cross-scale network patterns. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization interaction case study social network graph graphics radial visualization algorithm design and analysis Gou, L. Zhang, X. compound graph treenetviz multiscale and cross-scale network and tree complexity theory tree data structures infovis11--239 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on TextFlow: Towards Better Understanding of Evolving Topics in Text. Understanding how topics evolve in text data is an important and challenging task. Although much work has been devoted to topic analysis, the study of topic evolution has largely been limited to individual topics. In this paper, we introduce TextFlow, a seamless integration of visualization and topic mining techniques, for analyzing various evolution patterns that emerge from multiple topics. We first extend an existing analysis technique to extract three-level features: the topic evolution trend, the critical event, and the keyword correlation. Then a coherent visualization that consists of three new visual components is designed to convey complex relationships between them. Through interaction, the topic mining model and visualization can communicate with each other to help users refine the analysis result and gain insights into the data progressively. Finally, two case studies are conducted to demonstrate the effectiveness and usefulness of TextFlow in helping users understand the major topic evolution patterns in time-varying text data. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis interaction tag clouds text Cui, W. Liu, S. Tan, L. Shi, C. Song, Y. Gao, Z. Qu, H. Tong, X. critical event hierarchical dirichlet process text visualization topic evolution text analysis infovis11--237 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Synthetic Generation of High-Dimensional Datasets. Generation of synthetic datasets is a common practice in many research areas. Such data is often generated to meet specific needs or certain conditions that may not be easily found in the original, real data. The nature of the data varies according to the application area and includes text, graphs, social or weather data, among many others. The common process to create such synthetic datasets is to implement small scripts or programs, restricted to small problems or to a specific application. In this paper we propose a framework designed to generate high dimensional datasets. Users can interactively create and navigate through multi dimensional datasets using a suitable graphical user-interface. The data creation is driven by statistical distributions based on a few user-defined parameters. First, a grounding dataset is created according to given inputs, and then structures and trends are included in selected dimensions and orthogonal projection planes. Furthermore, our framework supports the creation of complex non-orthogonal trends and classified datasets. It can successfully be used to create synthetic datasets simulating important trends as multidimensional clusters, correlations and outliers. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on social multivariate data text scattering parameters Albuquerque, G. Lowe, T. Magnor, M. synthetic data generation high-dimensional data interaction correlation data processing probability density function infovis11--234 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Stereoscopic Highlighting: 2D Graph Visualization on Stereo Displays. In this paper we present a new technique and prototype graph visualization system, stereoscopic highlighting, to help answer accessibility and adjacency queries when interacting with a node-link diagram. Our technique utilizes stereoscopic depth to highlight regions of interest in a 2D graph by projecting these parts onto a plane closer to the viewpoint of the user. This technique aims to isolate and magnify specific portions of the graph that need to be explored in detail without resorting to other highlighting techniques like color or motion, which can then be reserved to encode other data attributes. This mechanism of stereoscopic highlighting also enables focus+context views by juxtaposing a detailed image of a region of interest with the overall graph, which is visualized at a further depth with correspondingly less detail. In order to validate our technique, we ran a controlled experiment with 16 subjects comparing static visual highlighting to stereoscopic highlighting on 2D and 3D graph layouts for a range of tasks. Our results show that while for most tasks the difference in performance between stereoscopic highlighting alone and static visual highlighting is not statistically significant, users performed better when both highlighting methods were used concurrently. In more complicated tasks, 3D layout with static visual highlighting outperformed 2D layouts with a single highlighting method. However, it did not outperform the 2D layout utilizing both highlighting techniques simultaneously. Based on these results, we conclude that stereoscopic highlighting is a promising technique that can significantly enhance graph visualizations for certain use cases. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis graph experiment Alper, B. graph visualization color graphics focus+context Hollerer, T. Kuchera-Morin, J. Forbes, A. stereo displays virtual reality stereo image processing two dimensional displays infovis11--233 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Skeleton-Based Edge Bundling for Graph Visualization. In this paper, we present a novel approach for constructing bundled layouts of general graphs. As layout cues for bundles, we use medial axes, or skeletons, of edges which are similar in terms of position information. We combine edge clustering, distance fields, and 2D skeletonization to construct progressively bundled layouts for general graphs by iteratively attracting edges towards the centerlines of level sets of their distance fields. Apart from clustering, our entire pipeline is image-based with an efficient implementation in graphics hardware. Besides speed and implementation simplicity, our method allows explicit control of the emphasis on structure of the bundled layout, i.e. the creation of strongly branching (organic-like) or smooth bundles. We demonstrate our method on several large real-world graphs. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on shape analysis clustering graph image edge detection transforms Hurter, C. Telea, A. Ersoy, O. hardware Paulovich, F.V. Cantareiro, G. graph layouts edge bundles image-based information visualization image processing smoothing methods infovis11--232 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Sequence Surveyor: Leveraging Overview for Scalable Genomic Alignment Visualization. In this paper, we introduce overview visualization tools for large-scale multiple genome alignment data. Genome alignment visualization and, more generally, sequence alignment visualization are an important tool for understanding genomic sequence data. As sequencing techniques improve and more data become available, greater demand is being placed on visualization tools to scale to the size of these new datasets. When viewing such large data, we necessarily cannot convey details, rather we specifically design overview tools to help elucidate large-scale patterns. Perceptual science, signal processing theory, and generality provide a framework for the design of such visualizations that can scale well beyond current approaches. We present Sequence Surveyor, a prototype that embodies these ideas for scalable multiple whole-genome alignment overview visualization. Sequence Surveyor visualizes sequences in parallel, displaying data using variable color, position, and aggregation encodings. We demonstrate how perceptual science can inform the design of visualization techniques that remain visually manageable at scale and how signal processing concepts can inform aggregation schemes that highlight global trends, outliers, and overall data distributions as the problem scales. These techniques allow us to visualize alignments with over 100 whole bacterial-sized genomes. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis overview theory color Albers, D. Dewey, C. Gleicher, M. bioinformatics visualization perception theory scalability issues visual design bioinformatics design methodology genomics infovis11--229 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Quality Metrics in High-Dimensional Data Visualization: An Overview and Systematization. In this paper, we present a systematization of techniques that use quality metrics to help in the visual exploration of meaningful patterns in high-dimensional data. In a number of recent papers, different quality metrics are proposed to automate the demanding search through large spaces of alternative visualizations (e.g., alternative projections or ordering), allowing the user to concentrate on the most promising visualizations suggested by the quality metrics. Over the last decade, this approach has witnessed a remarkable development but few reflections exist on how these methods are related to each other and how the approach can be developed further. For this purpose, we provide an overview of approaches that use quality metrics in high-dimensional data visualization and propose a systematization based on a thorough literature review. We carefully analyze the papers and derive a set of factors for discriminating the quality metrics, visualization techniques, and the process itself. The process is described through a reworked version of the well-known information visualization pipeline. We demonstrate the usefulness of our model by applying it to several existing approaches that use quality metrics, and we provide reflections on implications of our model for future research. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization metrics overview high-dimensional data Bertini, E. high-dimensional data visualization quality metrics measurements infovis11--227 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Product Plots. We propose a new framework for visualising tables of counts, proportions and probabilities. We call our framework product plots, alluding to the computation of area as a product of height and width, and the statistical concept of generating a joint distribution from the product of conditional and marginal distributions. The framework, with extensions, is sufficient to encompass over 20 visualisations previously described in fields of statistical graphics and infovis, including bar charts, mosaic plots, treemaps, equal area plots and fluctuation diagrams. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis Wickham, H. Hofmann, H. statistics bar chart conditional distribution joint distribution mosaic plot treemap probability statistical analysis infovis11--226 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Parallel Edge Splatting for Scalable Dynamic Graph Visualization. We present a novel dynamic graph visualization technique based on node-link diagrams. The graphs are drawn side-byside from left to right as a sequence of narrow stripes that are placed perpendicular to the horizontal time line. The hierarchically organized vertices of the graphs are arranged on vertical, parallel lines that bound the stripes; directed edges connect these vertices from left to right. To address massive overplotting of edges in huge graphs, we employ a splatting approach that transforms the edges to a pixel-based scalar field. This field represents the edge densities in a scalable way and is depicted by non-linear color mapping. The visualization method is complemented by interaction techniques that support data exploration by aggregation, filtering, brushing, and selective data zooming. Furthermore, we formalize graph patterns so that they can be interactively highlighted on demand. A case study on software releases explores the evolution of call graphs extracted from the JUnit open source software project. In a second application, we demonstrate the scalability of our approach by applying it to a bibliography dataset containing more than 1.5 million paper titles from 60 years of research history producing a vast amount of relations between title words. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis interaction case study graph color graphics encoding image edge detection Burch, M. Weiskopf, D. brushing pixel zooming history Vehlow, C. Beck, F. Diehl, S. dynamic graph visualization graph splatting software evolution software visualization software engineering infovis11--223 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on MoleView: An Attribute and Structure-Based Semantic Lens for Large Element-Based Plots. We present MoleView, a novel technique for interactive exploration of multivariate relational data. Given a spatial embedding of the data, in terms of a scatter plot or graph layout, we propose a semantic lens which selects a specific spatial and attribute-related data range. The lens keeps the selected data in focus unchanged and continuously deforms the data out of the selection range in order to maintain the context around the focus. Specific deformations include distance-based repulsion of scatter plot points, deforming straight-line node-link graph drawings, and as varying the simplification degree of bundled edge graph layouts. Using a brushing-based technique, we further show the applicability of our semantic lens for scenarios requiring a complex selection of the zones of interest. Our technique is simple to implement and provides real-time performance on large datasets. We demonstrate our technique with actual data from air and road traffic control, medical imaging, and software comprehension applications. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization shape analysis graph lenses brushing graph layout Hurter, C. Telea, A. Ersoy, O. semantic lenses attribute filtering graph bundling magic lenses filtering theory semantics infovis11--220 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Local Affine Multidimensional Projection. Multidimensional projection techniques have experienced many improvements lately, mainly regarding computational times and accuracy. However, existing methods do not yet provide flexible enough mechanisms for visualization-oriented fully interactive applications. This work presents a new multidimensional projection technique designed to be more flexible and versatile than other methods. This novel approach, called Local Affine Multidimensional Projection (LAMP), relies on orthogonal mapping theory to build accurate local transformations that can be dynamically modified according to user knowledge. The accuracy, flexibility and computational efficiency of LAMP is confirmed by a comprehensive set of comparisons. LAMP's versatility is exploited in an application which seeks to correlate data that, in principle, has no connection as well as in visual exploration of textual documents. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on theory Joia, P. Coimbra, D. Cuminato, J.A. Paulovich, F.V. Nonato, L.G. high dimensional data multidimensional projection visual data mining data mining minimization robustness infovis11--213 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on In Situ Exploration of Large Dynamic Networks. The analysis of large dynamic networks poses a challenge in many fields, ranging from large bot-nets to social networks. As dynamic networks exhibit different characteristics, e.g., being of sparse or dense structure, or having a continuous or discrete time line, a variety of visualization techniques have been specifically designed to handle these different aspects of network structure and time. This wide range of existing techniques is well justified, as rarely a single visualization is suitable to cover the entire visual analysis. Instead, visual representations are often switched in the course of the exploration of dynamic graphs as the focus of analysis shifts between the temporal and the structural aspects of the data. To support such a switching in a seamless and intuitive manner, we introduce the concept of in situ visualization– a novel strategy that tightly integrates existing visualization techniques for dynamic networks. It does so by allowing the user to interactively select in a base visualization a region for which a different visualization technique is then applied and embedded in the selection made. This permits to change the way a locally selected group of data items, such as nodes or time points, are shown – right in the place where they are positioned, thus supporting the user's overall mental map. Using this approach, a user can switch seamlessly between different visual representations to adapt a region of a base visualization to the specifics of the data within it or to the current analysis focus. This paper presents and discusses the in situ visualization strategy and its implications for dynamic graph visualization. Furthermore, it illustrates its usefulness by employing it for the visual exploration of dynamic networks from two different fields: model versioning and wireless mesh networks. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization social network graph graphics Hadlak, S. Schulz, H. Schumann, H. dynamic graph data multi-focus+context multiform visualization infovis11--212 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Improved Similarity Trees and their Application to Visual Data Classification. An alternative form to multidimensional projections for the visual analysis of data represented in multidimensional spaces is the deployment of similarity trees, such as Neighbor Joining trees. They organize data objects on the visual plane emphasizing their levels of similarity with high capability of detecting and separating groups and subgroups of objects. Besides this similarity-based hierarchical data organization, some of their advantages include the ability to decrease point clutter; high precision; and a consistent view of the data set during focusing, offering a very intuitive way to view the general structure of the data set as well as to drill down to groups and subgroups of interest. Disadvantages of similarity trees based on neighbor joining strategies include their computational cost and the presence of virtual nodes that utilize too much of the visual space. This paper presents a highly improved version of the similarity tree technique. The improvements in the technique are given by two procedures. The first is a strategy that replaces virtual nodes by promoting real leaf nodes to their place, saving large portions of space in the display and maintaining the expressiveness and precision of the technique. The second improvement is an implementation that significantly accelerates the algorithm, impacting its use for larger data sets. We also illustrate the applicability of the technique in visual data mining, showing its advantages to support visual classification of data sets, with special attention to the case of image classification. We demonstrate the capabilities of the tree for analysis and iterative manipulation and employ those capabilities to support evolving to a satisfactory data organization and classification. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization data mining Paiva, J.G. Florian, L. Pedrini, H. Telles, G.P. Minghim, R. image classification multidimensional projection similarity trees algorithm design and analysis biomedical image processing image classification phylogeny infovis11--209 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Human-Centered Approaches in Geovisualization Design: Investigating Multiple Methods Through a Long-Term Case Study. Working with three domain specialists we investigate human-centered approaches to geovisualization following an ISO13407 taxonomy covering context of use, requirements and early stages of design. Our case study, undertaken over three years, draws attention to repeating trends: that generic approaches fail to elicit adequate requirements for geovis application design; that the use of real data is key to understanding needs and possibilities; that trust and knowledge must be built and developed with collaborators. These processes take time but modified human-centred approaches can be effective. A scenario developed through contextual inquiry but supplemented with domain data and graphics is useful to geovis designers. Wireframe, paper and digital prototypes enable successful communication between specialist and geovis domains when incorporating real and interesting data, prompting exploratory behaviour and eliciting previously unconsidered requirements. Paper prototypes are particularly successful at eliciting suggestions, especially for novel visualization. Enabling specialists to explore their data freely with a digital prototype is as effective as using a structured task protocol and is easier to administer. Autoethnography has potential for framing the design process. We conclude that a common understanding of context of use, domain data and visualization possibilities are essential to successful geovis design and develop as this progresses. HC approaches can make a significant contribution here. However, modified approaches, applied with flexibility, are most promising. We advise early, collaborative engagement with data – through simple, transient visual artefacts supported by data sketches and existing designs – before moving to successively more sophisticated data wireframes and data prototypes. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization case study Dykes, J. geovisualization taxonomy geovisualization Lloyd, D. evaluation context of use design field study prototypes requirements sketching domain specific languages human factors taxonomy infovis11--205 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Focus+Context Metro Maps. We introduce a focus+context method to visualize a complicated metro map of a modern city on a small displaying area. The context of our work is with regard the popularity of mobile devices. The best route to the destination, which can be obtained from the arrival time of trains, is highlighted. The stations on the route enjoy larger spaces, whereas the other stations are rendered smaller and closer to fit the whole map into a screen. To simplify the navigation and route planning for visitors, we formulate various map characteristics such as octilinear transportation lines and regular station distances into energy terms. We then solve for the optimal layout in a least squares sense. In addition, we label the names of stations that are on the route of a passenger according to human preferences, occlusions, and consistencies of label positions using the graph cuts method. Our system achieves real-time performance by being able to report instant information because of the carefully designed energy terms. We apply our method to layout a number of metro maps and show the results and timing statistics to demonstrate the feasibility of our technique. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on graph graphics optimization optimization focus+context navigation statistics Wang, Y. Chi, M. focus+context visualization graph labeling metro map octilinear layout layout nonlinear distortion infovis11--201 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Flexible Linked Axes for Multivariate Data Visualization. Multivariate data visualization is a classic topic, for which many solutions have been proposed, each with its own strengths and weaknesses. In standard solutions the structure of the visualization is fixed, we explore how to give the user more freedom to define visualizations. Our new approach is based on the usage of Flexible Linked Axes: The user is enabled to define a visualization by drawing and linking axes on a canvas. Each axis has an associated attribute and range, which can be adapted. Links between pairs of axes are used to show data in either scatter plot- or Parallel Coordinates Plot-style. Flexible Linked Axes enable users to define a wide variety of different visualizations. These include standard methods, such as scatter plot matrices, radar charts, and PCPs [11]; less well known approaches, such as Hyperboxes [1], TimeWheels [17], and many-to-many relational parallel coordinate displays [14]; and also custom visualizations, consisting of combinations of scatter plots and PCPs. Furthermore, our method allows users to define composite visualizations that automatically support brushing and linking. We have discussed our approach with ten prospective users, who found the concept easy to understand and highly promising. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis parallel coordinates histograms van Wijk, J.J. multivariate data brushing Claessen, J.H.T. parallel coordinates plot scatterplot visualization scattering parameters infovis11--197 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Exploring Uncertainty in Geodemographics with Interactive Graphics. Geodemographic classifiers characterise populations by categorising geographical areas according to the demographic and lifestyle characteristics of those who live within them. The dimension-reducing quality of such classifiers provides a simple and effective means of characterising population through a manageable set of categories, but inevitably hides heterogeneity, which varies within and between the demographic categories and geographical areas, sometimes systematically. This may have implications for their use, which is widespread in government and commerce for planning, marketing and related activities. We use novel interactive graphics to delve into OAC – a free and open geodemographic classifier that classifies the UK population in over 200,000 small geographical areas into 7 super-groups, 21 groups and 52 sub-groups. Our graphics provide access to the original 41 demographic variables used in the classification and the uncertainty associated with the classification of each geographical area on-demand. It also supports comparison geographically and by category. This serves the dual purpose of helping understand the classifier itself leading to its more informed use and providing a more comprehensive view of population in a comprehensible manner. We assess the impact of these interactive graphics on experienced OAC users who explored the details of the classification, its uncertainty and the nature of between – and within – class variation and then reflect on their experiences. Visualization of the complexities and subtleties of the classification proved to be a thought-provoking exercise both confirming and challenging users' understanding of population, the OAC classifier and the way it is used in their organisations. Users identified three contexts for which the techniques were deemed useful in the context of local government, confirming the validity of the proposed methods. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis Wood, J. Dykes, J. Slingsby, A. cartography visualization uncertainty geodemographics oac classification uncertainty classification demographics infovis11--196 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Exploring Ambient and Artistic Visualization for Residential Energy Use Feedback. Providing effective feedback on resource consumption in the home is a key challenge of environmental conservation efforts. One promising approach for providing feedback about residential energy consumption is the use of ambient and artistic visualizations. Pervasive computing technologies enable the integration of such feedback into the home in the form of distributed point-of-consumption feedback devices to support decision-making in everyday activities. However, introducing these devices into the home requires sensitivity to the domestic context. In this paper we describe three abstract visualizations and suggest four design requirements that this type of device must meet to be effective: pragmatic, aesthetic, ambient, and ecological. We report on the findings from a mixed methods user study that explores the viability of using ambient and artistic feedback in the home based on these requirements. Our findings suggest that this approach is a viable way to provide resource use feedback and that both the aesthetics of the representation and the context of use are important elements that must be considered in this design space. user study 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization aesthetics Rodgers, J. Bartram, L. ambient visualization casual infovis distributed visualization informative art sustainability art feedback real time systems resource management infovis11--195 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Exploratory Analysis of Time-Series with ChronoLenses. Visual representations of time-series are useful for tasks such as identifying trends, patterns and anomalies in the data. Many techniques have been devised to make these visual representations more scalable, enabling the simultaneous display of multiple variables, as well as the multi-scale display of time-series of very high resolution or that span long time periods. There has been comparatively little research on how to support the more elaborate tasks associated with the exploratory visual analysis of timeseries, e.g., visualizing derived values, identifying correlations, or discovering anomalies beyond obvious outliers. Such tasks typically require deriving new time-series from the original data, trying different functions and parameters in an iterative manner. We introduce a novel visualization technique called ChronoLenses, aimed at supporting users in such exploratory tasks. ChronoLenses perform on-the-fly transformation of the data points in their focus area, tightly integrating visual analysis with user actions, and enabling the progressive construction of advanced visual analysis pipelines. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on focus+context data visualization time series analysis Zhao, J. Chevalier, F. Pietriga, E. Balakrishnan, R. exploratory visualization interaction techniques lens time-series data lenses rendering (computer graphics) transforms infovis11--193 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Evaluation of Traditional, Orthogonal, and Radial Tree Diagrams by an Eye Tracking Study. Node-link diagrams are an effective and popular visualization approach for depicting hierarchical structures and for showing parent-child relationships. In this paper, we present the results of an eye tracking experiment investigating traditional, orthogonal, and radial node-link tree layouts as a piece of empirical basis for choosing between those layouts. Eye tracking was used to identify visual exploration behaviors of participants that were asked to solve a typical hierarchy exploration task by inspecting a static tree diagram: finding the least common ancestor of a given set of marked leaf nodes. To uncover exploration strategies, we examined fixation points, duration, and saccades of participants' gaze trajectories. For the non-radial diagrams, we additionally investigated the effect of diagram orientation by switching the position of the root node to each of the four main orientations. We also recorded and analyzed correctness of answers as well as completion times in addition to the eye movement data. We found out that traditional and orthogonal tree layouts significantly outperform radial tree layouts for the given task. Furthermore, by applying trajectory analysis techniques we uncovered that participants cross-checked their task solution more often in the radial than in the non-radial layouts. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization evaluation trajectory experiment analysis of variance radial hierarchy Burch, M. Konevtsova, N. Heinrich, J. Hoeferlin, M. Weiskopf, D. hierarchy visualization eye-tracking node-link layout user study hierarchical systems tracking upper bound infovis11--192 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Evaluation of Artery Visualizations for Heart Disease Diagnosis. Heart disease is the number one killer in the United States, and finding indicators of the disease at an early stage is critical for treatment and prevention. In this paper we evaluate visualization techniques that enable the diagnosis of coronary artery disease. A key physical quantity of medical interest is endothelial shear stress (ESS). Low ESS has been associated with sites of lesion formation and rapid progression of disease in the coronary arteries. Having effective visualizations of a patient's ESS data is vital for the quick and thorough non-invasive evaluation by a cardiologist. We present a task taxonomy for hemodynamics based on a formative user study with domain experts. Based on the results of this study we developed HemoVis, an interactive visualization application for heart disease diagnosis that uses a novel 2D tree diagram representation of coronary artery trees. We present the results of a formal quantitative user study with domain experts that evaluates the effect of 2D versus 3D artery representations and of color maps on identifying regions of low ESS. We show statistically significant results demonstrating that our 2D visualizations are more accurate and efficient than 3D representations, and that a perceptually appropriate color map leads to fewer diagnostic mistakes than a rainbow color map. user study 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis evaluation color taxonomy Borkin, M. Gajos, K. Peters, A. Mitsouras, D. Melchionna, S. Rybicki, F. Feldman, C. Pfister, H. quantitative evaluation biomedical and medical visualization qualitative evaluation arteries blood flow heart three dimensional displays infovis11--191 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Drawing Road Networks with Focus Regions. Mobile users of maps typically need detailed information about their surroundings plus some context information about remote places. In order to avoid that the map partly gets too dense, cartographers have designed mapping functions that enlarge a user-defined focus region - such functions are sometimes called fish-eye projections. The extra map space occupied by the enlarged focus region is compensated by distorting other parts of the map. We argue that, in a map showing a network of roads relevant to the user, distortion should preferably take place in those areas where the network is sparse. Therefore, we do not apply a predefined mapping function. Instead, we consider the road network as a graph whose edges are the road segments. We compute a new spatial mapping with a graph-based optimization approach, minimizing the square sum of distortions at edges. Our optimization method is based on a convex quadratic program (CQP); CQPs can be solved in polynomial time. Important requirements on the output map are expressed as linear inequalities. In particular, we show how to forbid edge crossings. We have implemented our method in a prototype tool. For instances of different sizes, our method generated output maps that were far less distorted than those generated with a predefined fish-eye projection. Future work is needed to automate the selection of roads relevant to the user. Furthermore, we aim at fast heuristics for application in real-time systems. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on network graph graph drawing graphics distortion Haunert, J. Sering, L. cartography fish-eye view optimization quadratic programming schematic maps cartography distortion measurement image analysis optimization quadratic programming visualization infovis11--190 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Divided Edge Bundling for Directional Network Data. The node-link diagram is an intuitive and venerable way to depict a graph. To reduce clutter and improve the readability of node-link views, Holten & van Wijk's force-directed edge bundling employs a physical simulation to spatially group graph edges. While both useful and aesthetic, this technique has shortcomings: it bundles spatially proximal edges regardless of direction, weight, or graph connectivity. As a result, high-level directional edge patterns are obscured. We present divided edge bundling to tackle these shortcomings. By modifying the forces in the physical simulation, directional lanes appear as an emergent property of edge direction. By considering graph topology, we only bundle edges related by graph structure. Finally, we aggregate edge weights in bundles to enable more accurate visualization of total bundle weights. We compare visualizations created using our technique to standard force-directed edge bundling, matrix diagrams, and clustered graphs; we find that divided edge bundling leads to visualizations that are easier to interpret and reveal both familiar and previously obscured patterns. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization matrix network graph Heer, J. graph visualization graphics Selassie, D. Heller, B. aggregation edge bundling node-link diagram physical simulation encoding image edge detection infovis11--187 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Developing and Evaluating Quilts for the Depiction of Large Layered Graphs. Traditional layered graph depictions such as flow charts are in wide use. Yet as graphs grow more complex, these depictions can become difficult to understand. Quilts are matrix-based depictions for layered graphs designed to address this problem. In this research, we first improve Quilts by developing three design alternatives, and then compare the best of these alternatives to better-known node-link and matrix depictions. A primary weakness in Quilts is their depiction of skip links, links that do not simply connect to a succeeding layer. Therefore in our first study, we compare Quilts using color-only, text-only, and mixed (color and text) skip link depictions, finding that path finding with the color-only depiction is significantly slower and less accurate, and that in certain cases, the mixed depiction offers an advantage over the text-only depiction. In our second study, we compare Quilts using the mixed depiction to node-link diagrams and centered matrices. Overall results show that users can find paths through graphs significantly faster with Quilts (46.6 secs) than with node-link (58.3 secs) or matrix (71.2 secs) diagrams. This speed advantage is still greater in large graphs (e.g. in 200 node graphs, 55.4 secs vs. 71.1 secs for node-link and 84.2 secs for matrix depictions). 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on matrix graph color text Bae, J. Watson, B. graph drawing layered graphs matrix based depiction node-link diagram analysis of variance atmospheric measurements graphics particle measurements time measurement infovis11--186 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Design Study of LineSets, a Novel Set Visualization Technique. Computing and visualizing sets of elements and their relationships is one of the most common tasks one performs when analyzing and organizing large amounts of data. Common representations of sets such as convex or concave geometries can become cluttered and difficult to parse when these sets overlap in multiple or complex ways, e.g., when multiple elements belong to multiple sets. In this paper, we present a design study of a novel set visual representation, LineSets, consisting of a curve connecting all of the set's elements. Our approach to design the visualization differs from traditional methodology used by the InfoVis community. We first explored the potential of the visualization concept by running a controlled experiment comparing our design sketches to results from the state-of-the-art technique. Our results demonstrated that LineSets are advantageous for certain tasks when compared to concave shapes. We discuss an implementation of LineSets based on simple heuristics and present a study demonstrating that our generated curves do as well as human-drawn ones. Finally, we present two applications of our technique in the context of search tasks on a map and community analysis tasks in social networks. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization shape analysis clustering social social network services design study experiment Alper, B. Henry Riche, N. Ramos, G. Czerwinski, M. set visualization faceted data visualization graph visualization accuracy geometry infovis11--185 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on D3 Data-Driven Documents. Data-Driven Documents (D3) is a novel representation-transparent approach to visualization for the web. Rather than hide the underlying scenegraph within a toolkit-specific abstraction, D3 enables direct inspection and manipulation of a native representation: the standard document object model (DOM). With D3, designers selectively bind input data to arbitrary document elements, applying dynamic transforms to both generate and modify content. We show how representational transparency improves expressiveness and better integrates with developer tools than prior approaches, while offering comparable notational efficiency and retaining powerful declarative components. Immediate evaluation of operators further simplifies debugging and allows iterative development. Additionally, we demonstrate how D3 transforms naturally enable animation and interaction with dramatic performance improvements over intermediate representations. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis interaction evaluation toolkit document animation Bostock, M. Ogievetsky, V. Heer, J. 2D graphics information visualization toolkits user interfaces cascading style sheets debugging information analysis infovis11--183 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Context-Preserving Visual Links. Evaluating, comparing, and interpreting related pieces of information are tasks that are commonly performed during visual data analysis and in many kinds of information-intensive work. Synchronized visual highlighting of related elements is a well-known technique used to assist this task. An alternative approach, which is more invasive but also more expressive is visual linking in which line connections are rendered between related elements. In this work, we present context-preserving visual links as a new method for generating visual links. The method specifically aims to fulfill the following two goals: first, visual links should minimize the occlusion of important information; second, links should visually stand out from surrounding information by minimizing visual interference. We employ an image-based analysis of visual saliency to determine the important regions in the original representation. A consequence of the image-based approach is that our technique is application-independent and can be employed in a large number of visual data analysis scenarios in which the underlying content cannot or should not be altered. We conducted a controlled experiment that indicates that users can find linked elements in complex visualizations more quickly and with greater subjective satisfaction than in complex visualizations in which plain highlighting is used. Context-preserving visual links were perceived as visually more attractive than traditional visual links that do not account for the context information. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis histograms occlusion experiment Steinberger, M. Waldner, M. Streit, M. Lex, A. Schmalstieg, D. visual links connectedness highlighting image-based routing saliency infovis11--181 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Composite Density Maps for Multivariate Trajectories. We consider moving objects as multivariate time-series. By visually analyzing the attributes, patterns may appear that explain why certain movements have occurred. Density maps as proposed by Scheepens et al. [25] are a way to reveal these patterns by means of aggregations of filtered subsets of trajectories. Since filtering is often not sufficient for analysts to express their domain knowledge, we propose to use expressions instead. We present a flexible architecture for density maps to enable custom, versatile exploration using multiple density fields. The flexibility comes from a script, depicted in this paper as a block diagram, which defines an advanced computation of a density field. We define six different types of blocks to create, compose, and enhance trajectories or density fields. Blocks are customized by means of expressions that allow the analyst to model domain knowledge. The versatility of our architecture is demonstrated with several maritime use cases developed with domain experts. Our approach is expected to be useful for the analysis of objects in other domains. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis Scheepens, R. Willems, N. van de Wetering, H. Andrienko, G. Andrienko, N. van Wijk, J.J. geographical information systems kernel density estimation multivariate data trajectories and raster maps computational modeling computer architecture trajectory infovis11--176 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on BirdVis: Visualizing and Understanding Bird Populations. Birds are unrivaled windows into biotic processes at all levels and are proven indicators of ecological well-being. Understanding the determinants of species distributions and their dynamics is an important aspect of ecology and is critical for conservation and management. Through crowdsourcing, since 2002, the eBird project has been collecting bird observation records. These observations, together with local-scale environmental covariates such as climate, habitat, and vegetation phenology have been a valuable resource for a global community of educators, land managers, ornithologists, and conservation biologists. By associating environmental inputs with observed patterns of bird occurrence, predictive models have been developed that provide a statistical framework to harness available data for predicting species distributions and making inferences about species-habitat associations. Understanding these models, however, is challenging because they require scientists to quantify and compare multiscale spatialtemporal patterns. A large series of coordinated or sequential plots must be generated, individually programmed, and manually composed for analysis. This hampers the exploration and is a barrier to making the cross-species comparisons that are essential for coordinating conservation and extracting important ecological information. To address these limitations, as part of a collaboration among computer scientists, statisticians, biologists and ornithologists, we have developed BirdVis, an interactive visualization system that supports the analysis of spatio-temporal bird distribution models. BirdVis leverages visualization techniques and uses them in a novel way to better assist users in the exploration of interdependencies among model parameters. Furthermore, the system allows for comparative visualization through coordinated views, providing an intuitive interface to identify relevant correlations and patterns. We justify our design decisions and present case studies that show how BirdVis has helped scientists obtain new evidence for existing hypotheses, as well as formulate new hypotheses in their domain. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization collaboration coordinated views Ferreira, N. Lins, L. Fink, D. Kelling, S. Wood, C. Freire, J. Silva, C. ornithology multiscale analysis spatial data species distribution models temporal data biological system modeling ornithology predictive models spatial databases tag clouds infovis11--175 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Benefitting InfoVis with Visual Difficulties. Many well-cited theories for visualization design state that a visual representation should be optimized for quick and immediate interpretation by a user. Distracting elements like decorative "chartjunk" or extraneous information are avoided so as not to slow comprehension. Yet several recent studies in visualization research provide evidence that non-efficient visual elements may benefit comprehension and recall on the part of users. Similarly, findings from studies related to learning from visual displays in various subfields of psychology suggest that introducing cognitive difficulties to visualization interaction can improve a user's understanding of important information. In this paper, we synthesize empirical results from cross-disciplinary research on visual information representations, providing a counterpoint to efficiency-based design theory with guidelines that describe how visual difficulties can be introduced to benefit comprehension and recall. We identify conditions under which the application of visual difficulties is appropriate based on underlying factors in visualization interaction like active processing and engagement. We characterize effective graph design as a trade-off between efficiency and learning difficulties in order to provide Information Visualization (InfoVis) researchers and practitioners with a framework for organizing explorations of graphs for which comprehension and recall are crucial. We identify implications of this view for the design and evaluation of information visualizations. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization interaction theory graph evaluation Hullman, J. Adar, E. Shah, P. desirable difficulites active processing cognitive efficiency engagement individual differences cognition psychology time factors infovis11--174 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on BallotMaps: Detecting Name Bias in Alphabetically Ordered Ballot Papers. The relationship between candidates' position on a ballot paper and vote rank is explored in the case of 5000 candidates for the UK 2010 local government elections in the Greater London area. This design study uses hierarchical spatially arranged graphics to represent two locations that affect candidates at very different scales: the geographical areas for which they seek election and the spatial location of their names on the ballot paper. This approach allows the effect of position bias to be assessed; that is, the degree to which the position of a candidate's name on the ballot paper influences the number of votes received by the candidate, and whether this varies geographically. Results show that position bias was significant enough to influence rank order of candidates, and in the case of many marginal electoral wards, to influence who was elected to government. Position bias was observed most strongly for Liberal Democrat candidates but present for all major political parties. Visual analysis of classification of candidate names by ethnicity suggests that this too had an effect on votes received by candidates, in some cases overcoming alphabetic name bias. The results found contradict some earlier research suggesting that alphabetic name bias was not sufficiently significant to affect electoral outcome and add new evidence for the geographic and ethnicity influences on voting behaviour. The visual approach proposed here can be applied to a wider range of electoral data and the patterns identified and hypotheses derived from them could have significant implications for the design of ballot papers and the conduct of fair elections. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis design study geographic Wood, J. Badawood, D. Dykes, J. Slingsby, A. voting bias democracy election geovisualization governance hierarchy treemap geospatial analysis local government nominations and elections infovis11--169 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Asymmetric Relations in Longitudinal Social Networks. In modeling and analysis of longitudinal social networks, visual exploration is used in particular to complement and inform other methods. The most common graphical representations for this purpose appear to be animations and small multiples of intermediate states, depending on the type of media available. We present an alternative approach based on matrix representation of gestaltlines (a combination of Tufte's sparklines with glyphs based on gestalt theory). As a result, we obtain static, compact, yet data-rich diagrams that support specifically the exploration of evolving dyadic relations and persistent group structure, although at the expense of cross-sectional network views and indirect linkages. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis social small multiples matrix theory network Brandes, U. Nick, B. glyphbased techniques network visualization social networks time series data visual knowledge discovery and representation social network services infovis11--167 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Arc Length-Based Aspect Ratio Selection. The aspect ratio of a plot has a dramatic impact on our ability to perceive trends and patterns in the data. Previous approaches for automatically selecting the aspect ratio have been based on adjusting the orientations or angles of the line segments in the plot. In contrast, we recommend a simple, effective method for selecting the aspect ratio: minimize the arc length of the data curve while keeping the area of the plot constant. The approach is parameterization invariant, robust to a wide range of inputs, preserves visual symmetries in the data, and is a compromise between previously proposed techniques. Further, we demonstrate that it can be effectively used to select the aspect ratio of contour plots. We believe arc length should become the default aspect ratio selection method. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on aspect ratio selection banking to 45 degrees orientation resolution length measurement ratio selection time series analysis infovis11--166 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Angular Histograms: Frequency-Based Visualizations for Large, High Dimensional Data. Parallel coordinates is a popular and well-known multivariate data visualization technique. However, one of their inherent limitations has to do with the rendering of very large data sets. This often causes an overplotting problem and the goal of the visual information seeking mantra is hampered because of a cluttered overview and non-interactive update rates. In this paper, we propose two novel solutions, namely, angular histograms and attribute curves. These techniques are frequency-based approaches to large, high-dimensional data visualization. They are able to convey both the density of underlying polylines and their slopes. Angular histogram and attribute curves offer an intuitive way for the user to explore the clustering, linear correlations and outliers in large data sets without the over-plotting and clutter problems associated with traditional parallel coordinates. We demonstrate the results on a wide variety of data sets including real-world, high-dimensional biological data. Finally, we compare our methods with the other popular frequency-based algorithms. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization parallel coordinates parallel coordinates overview high-dimensional data clustering Geng, Z. Peng, Z. Laramee, R.S. Roberts, J.C. Walker, R. angular histogram attribute curves histograms vectors infovis11--163 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Adaptive Privacy-Preserving Visualization Using Parallel Coordinates. Current information visualization techniques assume unrestricted access to data. However, privacy protection is a key issue for a lot of real-world data analyses. Corporate data, medical records, etc. are rich in analytical value but cannot be shared without first going through a transformation step where explicit identifiers are removed and the data is sanitized. Researchers in the field of data mining have proposed different techniques over the years for privacy-preserving data publishing and subsequent mining techniques on such sanitized data. A well-known drawback in these methods is that for even a small guarantee of privacy, the utility of the datasets is greatly reduced. In this paper, we propose an adaptive technique for privacy preser vation in parallel coordinates. Based on knowledge about the sensitivity of the data, we compute a clustered representation on the fly, which allows the user to explore the data without breaching privacy. Through the use of screen-space privacy metrics, the technique adapts to the user's screen parameters and interaction. We demonstrate our method in a case study and discuss potential attack scenarios. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization parallel coordinates data mining metrics interaction case study Dasgupta, A. Kosara, R. parallel coordinates clustering privacy clustering algorithms data privacy privacy infovis11--160 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on A Study on Dual-Scale Data Charts. We present the results of a user study that compares different ways of representing Dual-Scale data charts. Dual-Scale charts incorporate two different data resolutions into one chart in order to emphasize data in regions of interest or to enable the comparison of data from distant regions. While some design guidelines exist for these types of charts, there is currently little empirical evidence on which to base their design. We fill this gap by discussing the design space of Dual-Scale cartesian-coordinate charts and by experimentally comparing the performance of different chart types with respect to elementary graphical perception tasks such as comparing lengths and distances. Our study suggests that cut-out charts which include collocated full context and focus are the best alternative, and that superimposed charts in which focus and context overlap on top of each other should be avoided. user study perception 2011 Isenberg, P. Bezerianos, A. InfoVis Visualization and Computer Graphics, IEEE Transactions on dual-scale charts focus+context quantitative experiment data visualization image color analysis quantization shape analysis terminology infovis11--257 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on Brushing dimensions - a dual visual analysis model for high-dimensional data. In many application fields, data analysts have to deal with datasets that contain many expressions per item. The effective analysis of such multivariate datasets is dependent on the user's ability to understand both the intrinsic dimensionality of the dataset as well as the distribution of the dependent values with respect to the dimensions. In this paper, we propose a visualization model that enables the joint interactive visual analysis of multivariate datasets with respect to their dimensions as well as with respect to the actual data values. We describe a dual setting of visualization and interaction in items space and in dimensions space. The visualization of items is linked to the visualization of dimensions with brushing and focus+context visualization. With this approach, the user is able to jointly study the structure of the dimensions space as well as the distribution of data items with respect to the dimensions. Even though the proposed visualization model is general, we demonstrate its application in the context of a DNA microarray data analysis. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on Turkay, C. Filzmoser, P. Hauser, H. brushing high-dimensional data interaction focus+context analytical models computational modeling data models data visualization principal component analysis high-dimensional data analysis interactive visual analysis infovis11--259 10/26/2011 Visualization and Computer Graphics, IEEE Transactions on CloudLines: Compact Display of Event Episodes in Multiple Time-Series. We propose incremental logarithmic time-series technique as a way to deal with time-based representations of large and dynamic event data sets in limited space. Modern data visualization problems in the domains of news analysis, network security and financial applications, require visual analysis of incremental data, which poses specific challenges that are normally not solved by static visualizations. The incremental nature of the data implies that visualizations have to necessarily change their content and still provide comprehensible representations. In particular, in this paper we deal with the need to keep an eye on recent events together with providing a context on the past and to make relevant patterns accessible at any scale. Our technique adapts to the incoming data by taking care of the rate at which data items occur and by using a decay function to let the items fade away according to their relevance. Since access to details is also important, we also provide a novel distortion magnifying lens technique which takes into account the distortions introduced by the logarithmic time scale to augment readability in selected areas of interest. We demonstrate the validity of our techniques by applying them on incremental data coming from online news streams in different time frames. 2011 InfoVis Visualization and Computer Graphics, IEEE Transactions on Bertini, E. Keim, D.A. Krstajic, M. network security financial distortion data visualization estimation event detection lenses time series analysis incremental visualization event based data lens distortion infovis12--189 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on A User Study on Curved Edges in Graph Visualization. Recently there has been increasing research interest in displaying graphs with curved edges to produce more readable visualizations. While there are several automatic techniques, little has been done to evaluate their effectiveness empirically. In this paper we present two experiments studying the impact of edge curvature on graph readability. The goal is to understand the advantages and disadvantages of using curved edges for common graph tasks compared to straight line segments, which are the conventional choice for showing edges in node-link diagrams. We included several edge variations: straight edges, edges with different curvature levels, and mixed straight and curved edges. During the experiments, participants were asked to complete network tasks including determination of connectivity, shortest path, node degree, and common neighbors. We also asked the participants to provide subjective ratings of the aesthetics of different edge types. The results show significant performance differences between the straight and curved edges and clear distinctions between variations of curved edges. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on network layout graph visualization user study visualization educational institutions evaluation aesthetics optimization user interfaces Xu, K. Rooney, C. Passmore, P. Ham, D. Nguyen, P.H. graph curved edges analysis of variance software infovis12--192 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Adaptive Composite Map Projections. All major web mapping services use the web Mercator projection. This is a poor choice for maps of the entire globe or areas of the size of continents or larger countries because the Mercator projection shows medium and higher latitudes with extreme areal distortion and provides an erroneous impression of distances and relative areas. The web Mercator projection is also not able to show the entire globe, as polar latitudes cannot be mapped. When selecting an alternative projection for information visualization, rivaling factors have to be taken into account, such as map scale, the geographic area shown, the map's height-to-width ratio, and the type of cartographic visualization. It is impossible for a single map projection to meet the requirements for all these factors. The proposed composite map projection combines several projections that are recommended in cartographic literature and seamlessly morphs map space as the user changes map scale or the geographic region displayed. The composite projection adapts the map's geometry to scale, to the map's height-to-width ratio, and to the central latitude of the displayed area by replacing projections and adjusting their parameters. The composite projection shows the entire globe including poles; it portrays continents or larger countries with less distortion (optionally without areal distortion); and it can morph to the web Mercator projection for maps showing small regions. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on geographic shape analysis distortion Jenny, B. html5 canvas multi-scale map web mercator web cartography web map projection web mapping continents decision trees earth interpolation mapping infovis12--193 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Algorithms for Labeling Focus Regions. In this paper, we investigate the problem of labeling point sites in focus regions of maps or diagrams. This problem occurs, for example, when the user of a mapping service wants to see the names of restaurants or other POIs in a crowded downtown area but keep the overview over a larger area. Our approach is to place the labels at the boundary of the focus region and connect each site with its label by a linear connection, which is called a leader. In this way, we move labels from the focus region to the less valuable context region surrounding it. In order to make the leader layout well readable, we present algorithms that rule out crossings between leaders and optimize other characteristics such as total leader length and distance between labels. This yields a new variant of the boundary labeling problem, which has been studied in the literature. Other than in traditional boundary labeling, where leaders are usually schematized polylines, we focus on leaders that are either straight-line segments or Bezier curves. Further, we present algorithms that, given the sites, find a position of the focus region that optimizes the above characteristics. We also consider a variant of the problem where we have more sites than space for labels. In this situation, we assume that the sites are prioritized by the user. Alternatively, we take a new facility-location perspective which yields a clustering of the sites. We label one representative of each cluster. If the user wishes, we apply our approach to the sites within a cluster, giving details on demand. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on clustering data visualization visual analytics geospatial analysis overview cluster Fink, M. Haunert, J. Schulz, A. Spoerhase, J. Wolff, A. focus+context techniques data clustering geographic/geospatial visualization mobile and ubiquitous visualization clustering methods gravity labels ubiquitous computing infovis12--196 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on An Empirical Model of Slope Ratio Comparisons. Comparing slopes is a fundamental graph reading task and the aspect ratio chosen for a plot influences how easy these comparisons are to make. According to Banking to 45¡, a classic design guideline first proposed and studied by Cleveland et al., aspect ratios that center slopes around 45¡ minimize errors in visual judgments of slope ratios. This paper revisits this earlier work. Through exploratory pilot studies that expand Cleveland et al.'s experimental design, we develop an empirical model of slope ratio estimation that fits more extreme slope ratio judgments and two common slope ratio estimation strategies. We then run two experiments to validate our model. In the first, we show that our model fits more generally than the one proposed by Cleveland et al. and we find that, in general, slope ratio errors are not minimized around 45¡. In the second experiment, we explore a novel hypothesis raised by our model: that visible baselines can substantially mitigate errors made in slope judgments. We conclude with an application of our model to aspect ratio selection. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on market research graph experiment data models Talbot, J. Gerth, J. Hanrahan, P. banking to 45 degrees aspect ratio selection orientation resolution slope perception approximation methods estimation predictive models slope analysis infovis12--197 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on An Empirical Study on Using Visual Embellishments in Visualization. In written and spoken communications, figures of speech (e.g., metaphors and synecdoche) are often used as an aid to help convey abstract or less tangible concepts. However, the benefits of using rhetorical illustrations or embellishments in visualization have so far been inconclusive. In this work, we report an empirical study to evaluate hypotheses that visual embellishments may aid memorization, visual search and concept comprehension. One major departure from related experiments in the literature is that we make use of a dual-task methodology in our experiment. This design offers an abstraction of typical situations where viewers do not have their full attention focused on visualization (e.g., in meetings and lectures). The secondary task introduces "divided attention", and makes the effects of visual embellishments more observable. In addition, it also serves as additional masking in memory-based trials. The results of this study show that visual embellishments can help participants better remember the information depicted in visualization. On the other hand, visual embellishments can have a negative impact on the speed of visual search. The results show a complex pattern as to the benefits of visual embellishments in helping participants grasp key concepts from visualization. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization Chen, M. experiment visualization evaluation Borgo, R. Abdul-Rahman, A. Mohamed, F. Grant, P.W. Reppa, I. Floridi, L. visual embellishments cognition icons long-term memory metaphors visual search working memory complexity theory grasping humans memory management speech infovis12--199 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Assessing the Effect of Visualizations on Bayesian Reasoning through Crowdsourcing. People have difficulty understanding statistical information and are unaware of their wrong judgments, particularly in Bayesian reasoning. Psychology studies suggest that the way Bayesian problems are represented can impact comprehension, but few visual designs have been evaluated and only populations with a specific background have been involved. In this study, a textual and six visual representations for three classic problems were compared using a diverse subject pool through crowdsourcing. Visualizations included area-proportional Euler diagrams, glyph representations, and hybrid diagrams combining both. Our study failed to replicate previous findings in that subjects' accuracy was remarkably lower and visualizations exhibited no measurable benefit. A second experiment confirmed that simply adding a visualization to a textual Bayesian problem is of little help, even when the text refers to the visualization, but suggests that visualizations are more effective when the text is given without numerical values. We discuss our findings and the need for more such experiments to be carried out on heterogeneous populations of non-experts. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on sociology statistical analysis glyph experiment text visualization crowdsourcing Fekete, J.-D. crowdsourcing Micallef, L. Dragicevic, P. bayesian reasoning euler diagrams base rate fallacy glyphs probabilistic judgment bayesian methods breast cancer infovis12--204 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Beyond Mouse and Keyboard: Expanding Design Considerations for Information Visualization Interactions. The importance of interaction to Information Visualization (InfoVis) and, in particular, of the interplay between interactivity and cognition is widely recognized [12, 15, 32, 55, 70]. This interplay, combined with the demands from increasingly large and complex datasets, is driving the increased significance of interaction in InfoVis. In parallel, there have been rapid advances in many facets of interaction technologies. However, InfoVis interactions have yet to take full advantage of these new possibilities in interaction technologies, as they largely still employ the traditional desktop, mouse, and keyboard setup of WIMP (Windows, Icons, Menus, and a Pointer) interfaces. In this paper, we reflect more broadly about the role of more "natural" interactions for InfoVis and provide opportunities for future research. We discuss and relate general HCI interaction models to existing InfoVis interaction classifications by looking at interactions from a novel angle, taking into account the entire spectrum of interactions. Our discussion of InfoVis-specific interaction design considerations helps us identify a series of underexplored attributes of interaction that can lead to new, more "natural," interaction techniques for InfoVis. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization interaction Lee, B. Riche, N.H. Carpendale, S. interaction human computer interaction Isenberg, P. information analysis cognition user interfaces design considerations nui (natural user interface) post-wimp instruments taxonomy infovis12--205 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Capturing the Design Space of Sequential Space-Filling Layouts. We characterize the design space of the algorithms that sequentially tile a rectangular area with smaller, fixed-surface, rectangles. This space consist of five independent dimensions: Order, Size, Score, Recurse and Phrase. Each of these dimensions describe a particular aspect of such layout tasks. This class of layouts is interesting, because, beyond encompassing simple grids, tables and trees, it also includes all kinds of treemaps involving the placement of rectangles. For instance, Slice and dice, Squarified, Strip and Pivot layouts are various points in this five dimensional space. Many classic statistics visualizations, such as 100% stacked bar charts, mosaic plots and dimensional stacking, are also instances of this class. A few new and potentially interesting points in this space are introduced, such as spiral treemaps and variations on the strip layout. The core algorithm is implemented as a JavaScript prototype that can be used as a layout component in a variety of InfoViz toolkits. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on layout statistics tree data structures algorithm design and analysis layout Baudel, T. Broeskema, B. dimensional stacking grids mosaic plots squarified and pivot variations) strip tables & tree layouts treemaps (slice and dice visualization models spirals infovis12--207 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Comparing Clusterings Using Bertin's Idea. Classifying a set of objects into clusters can be done in numerous ways, producing different results. They can be visually compared using contingency tables [27], mosaicplots [13], fluctuation diagrams [15], tableplots [20] , (modified) parallel coordinates plots [28], Parallel Sets plots [18] or circos diagrams [19]. Unfortunately the interpretability of all these graphical displays decreases rapidly with the numbers of categories and clusterings. In his famous book A Semiology of Graphics [5] Bertin writes "the discovery of an ordered concept appears as the ultimate point in logical simplification since it permits reducing to a single instant the assimilation of series which previously required many instants of study". Or in more everyday language, if you use good orderings you can see results immediately that with other orderings might take a lot of effort. This is also related to the idea of effect ordering [12], that data should be organised to reflect the effect you want to observe. This paper presents an efficient algorithm based on Bertin's idea and concepts related to Kendall's t [17], which finds informative joint orders for two or more nominal classification variables. We also show how these orderings improve the various displays and how groups of corresponding categories can be detected using a top-down partitioning algorithm. Different clusterings based on data on the environmental performance of cars sold in Germany are used for illustration. All presented methods are available in the R package extracat which is used to compute the optimized orderings for the example dataset. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on parallel coordinates nominal optimization Pilhofer, A. Gribov, A. Unwin, A. order optimization classification fluctuation diagrams seriation classification clustering algorithms graphics stress measurement infovis12--208 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Compressed Adjacency Matrices: Untangling Gene Regulatory Networks. We present a novel technique-Compressed Adjacency Matrices-for visualizing gene regulatory networks. These directed networks have strong structural characteristics: out-degrees with a scale-free distribution, in-degrees bound by a low maximum, and few and small cycles. Standard visualization techniques, such as node-link diagrams and adjacency matrices, are impeded by these network characteristics. The scale-free distribution of out-degrees causes a high number of intersecting edges in node-link diagrams. Adjacency matrices become space-inefficient due to the low in-degrees and the resulting sparse network. Compressed adjacency matrices, however, exploit these structural characteristics. By cutting open and rearranging an adjacency matrix, we achieve a compact and neatly-arranged visualization. Compressed adjacency matrices allow for easy detection of subnetworks with a specific structure, so-called motifs, which provide important knowledge about gene regulatory networks to domain experts. We summarize motifs commonly referred to in the literature, and relate them to network analysis tasks common to the visualization domain. We show that a user can easily find the important motifs in compressed adjacency matrices, and that this is hard in standard adjacency matrix and node-link diagrams. We also demonstrate that interaction techniques for standard adjacency matrices can be used for our compressed variant. These techniques include rearrangement clustering, highlighting, and filtering. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on clustering network layout interaction visualization standards matrix Dinkla, K. Westenberg, M.A. van Wijk, J.J. network adjacency matrix gene regulation scale-free bismuth computer aided manufacturing proteins sparse matrices infovis12--212 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Design Considerations for Optimizing Storyline Visualizations. Storyline visualization is a technique used to depict the temporal dynamics of social interactions. This visualization technique was first introduced as a hand-drawn illustration in XKCD's "Movie Narrative Charts" [21]. If properly constructed, the visualization can convey both global trends and local interactions in the data. However, previous methods for automating storyline visualizations are overly simple, failing to achieve some of the essential principles practiced by professional illustrators. This paper presents a set of design considerations for generating aesthetically pleasing and legible storyline visualizations. Our layout algorithm is based on evolutionary computation, allowing us to effectively incorporate multiple objective functions. We show that the resulting visualizations have significantly improved aesthetics and legibility compared to existing techniques. social 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization layout Ma, K.-L. design study motion pictures design methodology aesthetics Tanahashi, Y. layout algorithm storyline visualization timeline visualization genomics white spaces infovis12--213 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Design Study Methodology: Reflections from the Trenches and the Stacks. Design studies are an increasingly popular form of problem-driven visualization research, yet there is little guidance available about how to do them effectively. In this paper we reflect on our combined experience of conducting twenty-one design studies, as well as reading and reviewing many more, and on an extensive literature review of other field work methods and methodologies. Based on this foundation we provide definitions, propose a methodological framework, and provide practical guidance for conducting design studies. We define a design study as a project in which visualization researchers analyze a specific real-world problem faced by domain experts, design a visualization system that supports solving this problem, validate the design, and reflect about lessons learned in order to refine visualization design guidelines. We characterize two axes - a task clarity axis from fuzzy to crisp and an information location axis from the domain expert's head to the computer - and use these axes to reason about design study contributions, their suitability, and uniqueness from other approaches. The proposed methodological framework consists of 9 stages: learn, winnow, cast, discover, design, implement, deploy, reflect, and write. For each stage we provide practical guidance and outline potential pitfalls. We also conducted an extensive literature survey of related methodological approaches that involve a significant amount of qualitative field work, and compare design study methodology to that of ethnography, grounded theory, and action research. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization collaboration visualization design study design study Sedlmair, M. Munzner, T. visualization algorithm design and analysis theory design methodology Meyer, M. framework methodology logic gates infovis12--214 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Different Strokes for Different Folks: Visual Presentation Design between Disciplines. We present an ethnographic study of design differences in visual presentations between academic disciplines. Characterizing design conventions between users and data domains is an important step in developing hypotheses, tools, and design guidelines for information visualization. In this paper, disciplines are compared at a coarse scale between four groups of fields: social, natural, and formal sciences; and the humanities. Two commonplace presentation types were analyzed: electronic slideshows and whiteboard "chalk talks". We found design differences in slideshows using two methods - coding and comparing manually-selected features, like charts and diagrams, and an image-based analysis using PCA called eigenslides. In whiteboard talks with controlled topics, we observed design behaviors, including using representations and formalisms from a participant's own discipline, that suggest authors might benefit from novel assistive tools for designing presentations. Based on these findings, we discuss opportunities for visualization ethnography and human-centered authoring tools for visual information. social 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization principal component analysis encoding visualization educational institutions design Gomez, S.R. Jianu, R. Ziemkiewicz, C. Guo, H. Laidlaw, D.H. presentations visual analysis buildings cognitive science semantics infovis12--215 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Does an Eye Tracker Tell the Truth about Visualizations?: Findings while Investigating Visualizations for Decision Making. For information visualization researchers, eye tracking has been a useful tool to investigate research participants' underlying cognitive processes by tracking their eye movements while they interact with visual techniques. We used an eye tracker to better understand why participants with a variant of a tabular visualization called `SimulSort' outperformed ones with a conventional table and typical one-column sorting feature (i.e., Typical Sorting). The collected eye-tracking data certainly shed light on the detailed cognitive processes of the participants; SimulSort helped with decision-making tasks by promoting efficient browsing behavior and compensatory decision-making strategies. However, more interestingly, we also found unexpected eye-tracking patterns with Simul- Sort. We investigated the cause of the unexpected patterns through a crowdsourcing-based study (i.e., Experiment 2), which elicited an important limitation of the eye tracking method: incapability of capturing peripheral vision. This particular result would be a caveat for other visualization researchers who plan to use an eye tracker in their studies. In addition, the method to use a testing stimulus (i.e., influential column) in Experiment 2 to verify the existence of such limitations would be useful for researchers who would like to verify their eye tracking results. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization market research experiment crowdsourcing crowdsourcing Kim, S. Dong, Z. Xian, H. Upatising, B. Soo, J. visualized decision making eye tracking limitations peripheral vision quantitative empirical study decision making research and development tracking infovis12--220 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Evaluating Sketchiness as a Visual Variable for the Depiction of Qualitative Uncertainty. We report on results of a series of user studies on the perception of four visual variables that are commonly used in the literature to depict uncertainty. To the best of our knowledge, we provide the first formal evaluation of the use of these variables to facilitate an easier reading of uncertainty in visualizations that rely on line graphical primitives. In addition to blur, dashing and grayscale, we investigate the use of `sketchiness' as a visual variable because it conveys visual impreciseness that may be associated with data quality. Inspired by work in non-photorealistic rendering and by the features of hand-drawn lines, we generate line trajectories that resemble hand-drawn strokes of various levels of proficiency-ranging from child to adult strokes-where the amount of perturbations in the line corresponds to the level of uncertainty in the data. Our results show that sketchiness is a viable alternative for the visualization of uncertainty in lines and is as intuitive as blur; although people subjectively prefer dashing style over blur, grayscale and sketchiness. We discuss advantages and limitations of each technique and conclude with design considerations on how to deploy these visual variables to effectively depict various levels of uncertainty for line marks. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis uncertainty uncertainty visualization uncertainty evaluation rendering (computer graphics) perception shape analysis Boukhelifa, N. Isenberg, T. Bezerianos, A. perception Fekete, J.-D. qualitative evaluation quantitative evaluation gray-scale infovis12--221 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Evaluating the Effect of Style in Information Visualization. This paper reports on a between-subject, comparative online study of three information visualization demonstrators that each displayed the same dataset by way of an identical scatterplot technique, yet were different in style in terms of visual and interactive embellishment. We validated stylistic adherence and integrity through a separate experiment in which a small cohort of participants assigned our three demonstrators to predefined groups of stylistic examples, after which they described the styles with their own words. From the online study, we discovered significant differences in how participants execute specific interaction operations, and the types of insights that followed from them. However, in spite of significant differences in apparent usability, enjoyability and usefulness between the style demonstrators, no variation was found on the self-reported depth, expert-rated depth, confidence or difficulty of the resulting insights. Three different methods of insight analysis have been applied, revealing how style impacts the creation of insights, ranging from higher-level pattern seeking to a more reflective and interpretative engagement with content, which is what underlies the patterns. As this study only forms the first step in determining how the impact of style in information visualization could be best evaluated, we propose several guidelines and tips on how to gather, compare and categorize insights through an online evaluation study, particularly in terms of analyzing the concise, yet wide variety of insights and observations in a trustworthy and reproducable manner. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization insight interaction evaluation experiment visualization usability visualization evaluation scatterplot design Vande Moere, A. Tomitsch, M. Wimmer, C. Christoph, B. Grechenig, T. aesthetics online study style user experience abstracts benchmark testing electronic mail subspace constraints usability infovis12--225 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Exploring Flow, Factors, and Outcomes of Temporal Event Sequences with the Outflow Visualization. Event sequence data is common in many domains, ranging from electronic medical records (EMRs) to sports events. Moreover, such sequences often result in measurable outcomes (e.g., life or death, win or loss). Collections of event sequences can be aggregated together to form event progression pathways. These pathways can then be connected with outcomes to model how alternative chains of events may lead to different results. This paper describes the Outflow visualization technique, designed to (1) aggregate multiple event sequences, (2) display the aggregate pathways through different event states with timing and cardinality, (3) summarize the pathways' corresponding outcomes, and (4) allow users to explore external factors that correlate with specific pathway state transitions. Results from a user study with twelve participants show that users were able to learn how to use Outflow easily with limited training and perform a range of tasks both accurately and rapidly. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization data visualization image color analysis layout user study information analysis Wongsuphasawat, K. Gotz, D. outflow state diagram state transition temporal event sequences sequential analysis infovis12--226 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Facilitating Discourse Analysis with Interactive Visualization. A discourse parser is a natural language processing system which can represent the organization of a document based on a rhetorical structure tree-one of the key data structures enabling applications such as text summarization, question answering and dialogue generation. Computational linguistics researchers currently rely on manually exploring and comparing the discourse structures to get intuitions for improving parsing algorithms. In this paper, we present DAViewer, an interactive visualization system for assisting computational linguistics researchers to explore, compare, evaluate and annotate the results of discourse parsers. An iterative user-centered design process with domain experts was conducted in the development of DAViewer. We report the results of an informal formative study of the system to better understand how the proposed visualization and interaction techniques are used in the real research environment. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis interaction text interaction techniques visualization algorithm design and analysis prototypes document standards Zhao, J. Chevalier, F. Collins, C. Balakrishnan, R. discourse structure computational linguisitics tree comparison visual analytics computational linguistics infovis12--229 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Graphical Overlays: Using Layered Elements to Aid Chart Reading. Reading a visualization can involve a number of tasks such as extracting, comparing or aggregating numerical values. Yet, most of the charts that are published in newspapers, reports, books, and on the Web only support a subset of these tasks. In this paper we introduce graphical overlays-visual elements that are layered onto charts to facilitate a larger set of chart reading tasks. These overlays directly support the lower-level perceptual and cognitive processes that viewers must perform to read a chart. We identify five main types of overlays that support these processes; the overlays can provide (1) reference structures such as gridlines, (2) highlights such as outlines around important marks, (3) redundant encodings such as numerical data labels, (4) summary statistics such as the mean or max and (5) annotations such as descriptive text for context. We then present an automated system that applies user-chosen graphical overlays to existing chart bitmaps. Our approach is based on the insight that generating most of these graphical overlays only requires knowing the properties of the visual marks and axes that encode the data, but does not require access to the underlying data values. Thus, our system analyzes the chart bitmap to extract only the properties necessary to generate the desired overlay. We also discuss techniques for generating interactive overlays that provide additional controls to viewers. We demonstrate several examples of each overlay type for bar, pie and line charts. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization market research image color analysis insight visualization text data mining statistics encoding visualization Kong, N. Agrawala, M. graph comprehension graphical perception overlays bars infovis12--230 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Graphical Tests for Power Comparison of Competing Designs. Lineups [4, 28] have been established as tools for visual testing similar to standard statistical inference tests, allowing us to evaluate the validity of graphical findings in an objective manner. In simulation studies [12] lineups have been shown as being efficient: the power of visual tests is comparable to classical tests while being much less stringent in terms of distributional assumptions made. This makes lineups versatile, yet powerful, tools in situations where conditions for regular statistical tests are not or cannot be met. In this paper we introduce lineups as a tool for evaluating the power of competing graphical designs. We highlight some of the theoretical properties and then show results from two studies evaluating competing designs: both studies are designed to go to the limits of our perceptual abilities to highlight differences between designs. We use both accuracy and speed of evaluation as measures of a successful design. The first study compares the choice of coordinate system: polar versus cartesian coordinates. The results show strong support in favor of cartesian coordinates in finding fast and accurate answers to spotting patterns. The second study is aimed at finding shift differences between distributions. Both studies are motivated by data problems that we have recently encountered, and explore using simulated data to evaluate the plot designs under controlled conditions. Amazon Mechanical Turk (MTurk) is used to conduct the studies. The lineups provide an effective mechanism for objectively evaluating plot designs. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on visual analytics statistical analysis evaluation accuracy data models Hofmann, H. Follett, L. Majumder, M. Cook, D. efficiency of displays lineups power comparison visual inference inference mechanisms observers infovis12--233 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on How Capacity Limits of Attention Influence Information Visualization Effectiveness. In this paper, we explore how the capacity limits of attention influence the effectiveness of information visualizations. We conducted a series of experiments to test how visual feature type (color vs. motion), layout, and variety of visual elements impacted user performance. The experiments tested users' abilities to (1) determine if a specified target is on the screen, (2) detect an odd-ball, deviant target, different from the other visible objects, and (3) gain a qualitative overview by judging the number of unique categories on the screen. Our results show that the severe capacity limits of attention strongly modulate the effectiveness of information visualizations, particularly the ability to detect unexpected information. Keeping in mind these capacity limits, we conclude with a set of design guidelines which depend on a visualization's intended use. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis layout color visualization perception overview layout accuracy Haroz, S. Whitney, D. attention color goal-oriented design motion nominal axis user study color time factors infovis12--236 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Intelligent Graph Layout Using Many Users' Input. In this paper, we propose a new strategy for graph drawing utilizing layouts of many sub-graphs supplied by a large group of people in a crowd sourcing manner. We developed an algorithm based on Laplacian constrained distance embedding to merge subgraphs submitted by different users, while attempting to maintain the topological information of the individual input layouts. To facilitate collection of layouts from many people, a light-weight interactive system has been designed to enable convenient dynamic viewing, modification and traversing between layouts. Compared with other existing graph layout algorithms, our approach can achieve more aesthetic and meaningful layouts with high user preference. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on layout graph graph layout algorithm design and analysis graph layout graph drawing crowdsourcing Yuan, X. Che, L. Hu, Y. Zhang, X. laplacian matrix crowd sourcing editing force directed layout merging stress model human factors laplace equations stress infovis12--237 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Interaction Support for Visual Comparison Inspired by Natural Behavior. Visual comparison is an intrinsic part of interactive data exploration and analysis. The literature provides a large body of existing solutions that help users accomplish comparison tasks. These solutions are mostly of visual nature and custom-made for specific data. We ask the question if a more general support is possible by focusing on the interaction aspect of comparison tasks. As an answer to this question, we propose a novel interaction concept that is inspired by real-world behavior of people comparing information printed on paper. In line with real-world interaction, our approach supports users (1) in interactively specifying pieces of graphical information to be compared, (2) in flexibly arranging these pieces on the screen, and (3) in performing the actual comparison of side-by-side and overlapping arrangements of the graphical information. Complementary visual cues and add-ons further assist users in carrying out comparison tasks. Our concept and the integrated interaction techniques are generally applicable and can be coupled with different visualization techniques. We implemented an interactive prototype and conducted a qualitative user study to assess the concept's usefulness in the context of three different visualization techniques. The obtained feedback indicates that our interaction techniques mimic the natural behavior quite well, can be learned quickly, and are easy to apply to visual comparison tasks. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization layout interaction navigation visualization Tominski, C. user study interaction techniques visualization shape Forsell, C. Johansson, J. human-computer interaction natural interaction visual comparison animation computers infovis12--238 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Interactive Level-of-Detail Rendering of Large Graphs. We propose a technique that allows straight-line graph drawings to be rendered interactively with adjustable level of detail. The approach consists of a novel combination of edge cumulation with density-based node aggregation and is designed to exploit common graphics hardware for speed. It operates directly on graph data and does not require precomputed hierarchies or meshes. As proof of concept, we present an implementation that scales to graphs with millions of nodes and edges, and discuss several example applications. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis hardware rendering (computer graphics) graph hierarchies Brandes, U. image edge detection Zinsmaier, M. Deussen, O. Strobelt, H. graph visualization opengl edge aggregation aggregates infovis12--244 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Living Liquid: Design and Evaluation of an Exploratory Visualization Tool for Museum Visitors. Interactive visualizations can allow science museum visitors to explore new worlds by seeing and interacting with scientific data. However, designing interactive visualizations for informal learning environments, such as museums, presents several challenges. First, visualizations must engage visitors on a personal level. Second, visitors often lack the background to interpret visualizations of scientific data. Third, visitors have very limited time at individual exhibits in museums. This paper examines these design considerations through the iterative development and evaluation of an interactive exhibit as a visualization tool that gives museumgoers access to scientific data generated and used by researchers. The exhibit prototype, Living Liquid, encourages visitors to ask and answer their own questions while exploring the time-varying global distribution of simulated marine microbes using a touchscreen interface. Iterative development proceeded through three rounds of formative evaluations using think-aloud protocols and interviews, each round informing a key visualization design decision: (1) what to visualize to initiate inquiry, (2) how to link data at the microscopic scale to global patterns, and (3) how to include additional data that allows visitors to pursue their own questions. Data from visitor evaluations suggests that, when designing visualizations for public audiences, one should (1) avoid distracting visitors from data that they should explore, (2) incorporate background information into the visualization, (3) favor understandability over scientific accuracy, and (4) layer data accessibility to structure inquiry. Lessons learned from this case study add to our growing understanding of how to use visualizations to actively engage learners with scientific data. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization data visualization image color analysis case study performance evaluation Ma, K.-L. evaluation motion pictures information analysis evaluation prototypes Ma, J. Liao, I. Frazier, J. informal learning environments science museums user interaction user studies learning systems infovis12--245 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Memorability of Visual Features in Network Diagrams. We investigate the cognitive impact of various layout features-symmetry, alignment, collinearity, axis alignment and orthogonality - on the recall of network diagrams (graphs). This provides insight into how people internalize these diagrams and what features should or shouldn't be utilised when designing static and interactive network-based visualisations. Participants were asked to study, remember, and draw a series of small network diagrams, each drawn to emphasise a particular visual feature. The visual features were based on existing theories of perception, and the task enabled visual processing at the visceral level only. Our results strongly support the importance of visual features such as symmetry, collinearity and orthogonality, while not showing any significant impact for node-alignment or parallel edges. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on network insight layout perception visualization educational institutions algorithm design and analysis graph layout shape image edge detection Marriott, K. Purchase, H. Wybrow, M. Goncu, C. network diagrams diagram recall experiment perceptual theories visual features topology infovis12--250 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Organizing Search Results with a Reference Map. We propose a method to highlight query hits in hierarchically clustered collections of interrelated items such as digital libraries or knowledge bases. The method is based on the idea that organizing search results similarly to their arrangement on a fixed reference map facilitates orientation and assessment by preserving a user's mental map. Here, the reference map is built from an MDS layout of the items in a Voronoi treemap representing their hierarchical clustering, and we use techniques from dynamic graph layout to align query results with the map. The approach is illustrated on an archive of newspaper articles. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on clustering graph treemap graph layout tree data structures Brandes, U. Nocaj, A. search results dynamic graph layout edge bundling mental map multidimensional scaling voronoi treemaps edge detection query processing search methods infovis12--251 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Perception of Visual Variables on Tiled Wall-Sized Displays for Information Visualization Applications. We present the results of two user studies on the perception of visual variables on tiled high-resolution wall-sized displays. We contribute an understanding of, and indicators predicting how, large variations in viewing distances and viewing angles affect the accurate perception of angles, areas, and lengths. Our work, thus, helps visualization researchers with design considerations on how to create effective visualizations for these spaces. The first study showed that perception accuracy was impacted most when viewers were close to the wall but differently for each variable (Angle, Area, Length). Our second study examined the effect of perception when participants could move freely compared to when they had a static viewpoint. We found that a far but static viewpoint was as accurate but less time consuming than one that included free motion. Based on our findings, we recommend encouraging viewers to stand further back from the display when conducting perception estimation tasks. If tasks need to be conducted close to the wall display, important information should be placed directly in front of the viewer or above, and viewers should be provided with an estimation of the distortion effects predicted by our work-or encouraged to physically navigate the wall in specific ways to reduce judgement error. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization data visualization visual analytics navigation perception Isenberg, P. distortion information analysis Bezerianos, A. perception wall-displays infovis12--252 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on PivotPaths: Strolling through Faceted Information Spaces. We present PivotPaths, an interactive visualization for exploring faceted information resources. During both work and leisure, we increasingly interact with information spaces that contain multiple facets and relations, such as authors, keywords, and citations of academic publications, or actors and genres of movies. To navigate these interlinked resources today, one typically selects items from facet lists resulting in abrupt changes from one subset of data to another. While filtering is useful to retrieve results matching specific criteria, it can be difficult to see how facets and items relate and to comprehend the effect of filter operations. In contrast, the PivotPaths interface exposes faceted relations as visual paths in arrangements that invite the viewer to `take a stroll' through an information space. PivotPaths supports pivot operations as lightweight interaction techniques that trigger gradual transitions between views. We designed the interface to allow for casual traversal of large collections in an aesthetically pleasing manner that encourages exploration and serendipitous discoveries. This paper shares the findings from our iterative design-and-evaluation process that included semi-structured interviews and a two-week deployment of PivotPaths applied to a large database of academic publications. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization layout interaction Riche, N.H. evaluation navigation filter database visualization motion pictures Dork, M. Ramos, G. Dumais, S. animation exploratory search information seeking interactivity node-link diagrams context facial animation information services infovis12--253 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on RankExplorer: Visualization of Ranking Changes in Large Time Series Data. For many applications involving time series data, people are often interested in the changes of item values over time as well as their ranking changes. For example, people search many words via search engines like Google and Bing every day. Analysts are interested in both the absolute searching number for each word as well as their relative rankings. Both sets of statistics may change over time. For very large time series data with thousands of items, how to visually present ranking changes is an interesting challenge. In this paper, we propose RankExplorer, a novel visualization method based on ThemeRiver to reveal the ranking changes. Our method consists of four major components: 1) a segmentation method which partitions a large set of time series curves into a manageable number of ranking categories; 2) an extended ThemeRiver view with embedded color bars and changing glyphs to show the evolution of aggregation values related to each ranking category over time as well as the content changes in each ranking category; 3) a trend curve to show the degree of ranking changes over time; 4) rich user interactions to support interactive exploration of ranking changes. We have applied our method to some real time series data and the case studies demonstrate that our method can reveal the underlying patterns related to ranking changes which might otherwise be obscured in traditional visualizations. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on Liu, S. Qu, H. data visualization market research image color analysis color time series statistics encoding interaction techniques Shi, C. Cui, W. Xu, P. Chen, W. themeriver time-series data ranking change time series analysis infovis12--255 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on RelEx: Visualization for Actively Changing Overlay Network Specifications. We present a network visualization design study focused on supporting automotive engineers who need to specify and optimize traffic patterns for in-car communication networks. The task and data abstractions that we derived support actively making changes to an overlay network, where logical communication specifications must be mapped to an underlying physical network. These abstractions are very different from the dominant use case in visual network analysis, namely identifying clusters and central nodes, that stems from the domain of social network analysis. Our visualization tool RelEx was created and iteratively refined through a full user-centered design process that included a full problem characterization phase before tool design began, paper prototyping, iterative refinement in close collaboration with expert users for formative evaluation, deployment in the field with real analysts using their own data, usability testing with non-expert users, and summative evaluation at the end of the deployment. In the summative post-deployment study, which entailed domain experts using the tool over several weeks in their daily practice, we documented many examples where the use of RelEx simplified or sped up their work compared to previous practices. social 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization network network topology evaluation collaboration design study collaboration usability design study Sedlmair, M. Munzner, T. Frank, A. Butz, A. network visualization automotive change management traffic optimization traffic routing automotive engineering change detection algorithms traffic control infovis12--256 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Representative Factor Generation for the Interactive Visual Analysis of High-Dimensional Data. Datasets with a large number of dimensions per data item (hundreds or more) are challenging both for computational and visual analysis. Moreover, these dimensions have different characteristics and relations that result in sub-groups and/or hierarchies over the set of dimensions. Such structures lead to heterogeneity within the dimensions. Although the consideration of these structures is crucial for the analysis, most of the available analysis methods discard the heterogeneous relations among the dimensions. In this paper, we introduce the construction and utilization of representative factors for the interactive visual analysis of structures in high-dimensional datasets. First, we present a selection of methods to investigate the sub-groups in the dimension set and associate representative factors with those groups of dimensions. Second, we introduce how these factors are included in the interactive visual analysis cycle together with the original dimensions. We then provide the steps of an analytical procedure that iteratively analyzes the datasets through the use of representative factors. We discuss how our methods improve the reliability and interpretability of the analysis process by enabling more informed selections of computational tools. Finally, we demonstrate our techniques on the analysis of brain imaging study results that are performed over a large group of subjects. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization high-dimensional data hierarchies principal component analysis data mining Turkay, C. Lundervold, A. Lundervold, A.J. Hauser, H. interactive visual analysis high-dimensional data analysis correlation gaussian distribution reliability infovis12--262 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Sketchy Rendering for Information Visualization. We present and evaluate a framework for constructing sketchy style information visualizations that mimic data graphics drawn by hand. We provide an alternative renderer for the Processing graphics environment that redefines core drawing primitives including line, polygon and ellipse rendering. These primitives allow higher-level graphical features such as bar charts, line charts, treemaps and node-link diagrams to be drawn in a sketchy style with a specified degree of sketchiness. The framework is designed to be easily integrated into existing visualization implementations with minimal programming modification or design effort. We show examples of use for statistical graphics, conveying spatial imprecision and for enhancing aesthetic and narrative qualities of visualization. We evaluate user perception of sketchiness of areal features through a series of stimulus-response tests in order to assess users' ability to place sketchiness on a ratio scale, and to estimate area. Results suggest relative area judgment is compromised by sketchy rendering and that its influence is dependent on the shape being rendered. They show that degree of sketchiness may be judged on an ordinal scale but that its judgement varies strongly between individuals. We evaluate higher-level impacts of sketchiness through user testing of scenarios that encourage user engagement with data visualization and willingness to critique visualization design. Results suggest that where a visualization is clearly sketchy, engagement may be increased and that attitudes to participating in visualization annotation are more positive. The results of our work have implications for effective information visualization design that go beyond the traditional role of sketching as a tool for prototyping or its use for an indication of general uncertainty. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization uncertainty rendering (computer graphics) visualization perception ordinal shape analysis Isenberg, P. Boukhelifa, N. Isenberg, T. Wood, J. Dykes, J. Slingsby, A. npr hand-drawn non-photorealistic rendering sketch uncertainty infovis12--263 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on SnapShot: Visualization to Propel Ice Hockey Analytics. Sports analysts live in a world of dynamic games flattened into tables of numbers, divorced from the rinks, pitches, and courts where they were generated. Currently, these professional analysts use R, Stata, SAS, and other statistical software packages for uncovering insights from game data. Quantitative sports consultants seek a competitive advantage both for their clients and for themselves as analytics becomes increasingly valued by teams, clubs, and squads. In order for the information visualization community to support the members of this blossoming industry, it must recognize where and how visualization can enhance the existing analytical workflow. In this paper, we identify three primary stages of today's sports analyst's routine where visualization can be beneficially integrated: 1) exploring a dataspace; 2) sharing hypotheses with internal colleagues; and 3) communicating findings to stakeholders.Working closely with professional ice hockey analysts, we designed and built SnapShot, a system to integrate visualization into the hockey intelligence gathering process. SnapShot employs a variety of information visualization techniques to display shot data, yet given the importance of a specific hockey statistic, shot length, we introduce a technique, the radial heat map. Through a user study, we received encouraging feedback from several professional analysts, both independent consultants and professional team personnel. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization radial user study human computer interaction Pileggi, H. Stolper, C.D. Boyle, J.M. Stasko, J. visual knowledge discovery human computer interaction hypothesis testing visual evidence visual knowledge representation games knowledge discovery sports equipment infovis12--264 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Spatial Text Visualization Using Automatic Typographic Maps. We present a method for automatically building typographic maps that merge text and spatial data into a visual representation where text alone forms the graphical features. We further show how to use this approach to visualize spatial data such as traffic density, crime rate, or demographic data. The technique accepts a vector representation of a geographic map and spatializes the textual labels in the space onto polylines and polygons based on user-defined visual attributes and constraints. Our sample implementation runs as a Web service, spatializing shape files from the OpenStreetMap project into typographic maps for any region. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization rendering (computer graphics) text geographic geospatial analysis Afzal, S. Maciejewski, R. Jang, Y. Elmqvist, N. Ebert, D.S. geovisualization label placement spatial data text visualization cities and towns spatial databases infovis12--265 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Stacking-Based Visualization of Trajectory Attribute Data. Visualizing trajectory attribute data is challenging because it involves showing the trajectories in their spatio-temporal context as well as the attribute values associated with the individual points of trajectories. Previous work on trajectory visualization addresses selected aspects of this problem, but not all of them. We present a novel approach to visualizing trajectory attribute data. Our solution covers space, time, and attribute values. Based on an analysis of relevant visualization tasks, we designed the visualization solution around the principle of stacking trajectory bands. The core of our approach is a hybrid 2D/3D display. A 2D map serves as a reference for the spatial context, and the trajectories are visualized as stacked 3D trajectory bands along which attribute values are encoded by color. Time is integrated through appropriate ordering of bands and through a dynamic query mechanism that feeds temporally aggregated information to a circular time display. An additional 2D time graph shows temporal information in full detail by stacking 2D trajectory bands. Our solution is equipped with analytical and interactive mechanisms for selecting and ordering of trajectories, and adjusting the color mapping, as well as coordinated highlighting and dedicated 3D navigation. We demonstrate the usefulness of our novel visualization by three examples related to radiation surveillance, traffic analysis, and maritime navigation. User feedback obtained in a small experiment indicates that our hybrid 2D/3D solution can be operated quite well. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization image color analysis trajectory interaction navigation navigation color dynamic query graph experiment visualization Tominski, C. Schumann, H. Andrienko, G. Andrienko, N. exploratory analysis spatio-temporal data trajectory attribute data infovis12--271 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Taxonomy-Based Glyph Design -- with a Case Study on Visualizing Workflows of Biological Experiments. Glyph-based visualization can offer elegant and concise presentation of multivariate information while enhancing speed and ease in visual search experienced by users. As with icon designs, glyphs are usually created based on the designers' experience and intuition, often in a spontaneous manner. Such a process does not scale well with the requirements of applications where a large number of concepts are to be encoded using glyphs. To alleviate such limitations, we propose a new systematic process for glyph design by exploring the parallel between the hierarchy of concept categorization and the ordering of discriminative capacity of visual channels. We examine the feasibility of this approach in an application where there is a pressing need for an efficient and effective means to visualize workflows of biological experiments. By processing thousands of workflow records in a public archive of biological experiments, we demonstrate that a cost-effective glyph design can be obtained by following a process of formulating a taxonomy with the aid of computation, identifying visual channels hierarchically, and defining application-specific abstraction and metaphors. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization case study taxonomy glyph hierarchy Chen, M. Maguire, E. Rocca-Serra, P. Sansone, S.-A. Davies, J. glyph-based techniques bioinformatics visualization design methodologies taxonomies glyph design infovis12--272 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on The DeepTree Exhibit: Visualizing the Tree of Life to Facilitate Informal Learning. In this paper, we present the DeepTree exhibit, a multi-user, multi-touch interactive visualization of the Tree of Life. We developed DeepTree to facilitate collaborative learning of evolutionary concepts. We will describe an iterative process in which a team of computer scientists, learning scientists, biologists, and museum curators worked together throughout design, development, and evaluation. We present the importance of designing the interactions and the visualization hand-in-hand in order to facilitate active learning. The outcome of this process is a fractal-based tree layout that reduces visual complexity while being able to capture all life on earth; a custom rendering and navigation engine that prioritizes visual appeal and smooth fly-through; and a multi-user interface that encourages collaborative exploration while offering guided discovery. We present an evaluation showing that the large dataset encouraged free exploration, triggers emotional responses, and facilitates visitor engagement and informal learning. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization layout evaluation navigation collaboration rendering (computer graphics) navigation Block, F. Horn, M.S. Phillips, B.C. Diamond, J. Evans, E.M. Shen, C. informal science education collaborative learning large tree visualizations multi-touch interaction information science phylogeny infovis12--275 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Understanding Pen and Touch Interaction for Data Exploration on Interactive Whiteboards. Current interfaces for common information visualizations such as bar graphs, line graphs, and scatterplots usually make use of the WIMP (Windows, Icons, Menus and a Pointer) interface paradigm with its frequently discussed problems of multiple levels of indirection via cascading menus, dialog boxes, and control panels. Recent advances in interface capabilities such as the availability of pen and touch interaction challenge us to re-think this and investigate more direct access to both the visualizations and the data they portray. We conducted a Wizard of Oz study to explore applying pen and touch interaction to the creation of information visualization interfaces on interactive whiteboards without implementing a plethora of recognizers. Our wizard acted as a robust and flexible pen and touch recognizer, giving participants maximum freedom in how they interacted with the system. Based on our qualitative analysis of the interactions our participants used, we discuss our insights about pen and touch interactions in the context of learnability and the interplay between pen and touch gestures. We conclude with suggestions for designing pen and touch enabled interactive visualization interfaces. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization interaction sociology statistical analysis Lee, B. Riche, N.H. Carpendale, S. interaction Walny, J. Johns, P. pen and touch wizard of oz data exploration whiteboard context awareness writing infovis12--279 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Visual Semiotics & Uncertainty Visualization: An Empirical Study. This paper presents two linked empirical studies focused on uncertainty visualization. The experiments are framed from two conceptual perspectives. First, a typology of uncertainty is used to delineate kinds of uncertainty matched with space, time, and attribute components of data. Second, concepts from visual semiotics are applied to characterize the kind of visual signification that is appropriate for representing those different categories of uncertainty. This framework guided the two experiments reported here. The first addresses representation intuitiveness, considering both visual variables and iconicity of representation. The second addresses relative performance of the most intuitive abstract and iconic representations of uncertainty on a map reading task. Combined results suggest initial guidelines for representing uncertainty and discussion focuses on practical applicability of results. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on uncertainty visual analytics uncertainty visualization uncertainty MacEachren, A.M. Roth, R.E. O'Brien, J. Li, B. Swingley, D. Gahegan, M. semiotics uncertainty categories visual variables semiotics syntactics infovis12--285 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Visualizing Flow of Uncertainty through Analytical Processes. Uncertainty can arise in any stage of a visual analytics process, especially in data-intensive applications with a sequence of data transformations. Additionally, throughout the process of multidimensional, multivariate data analysis, uncertainty due to data transformation and integration may split, merge, increase, or decrease. This dynamic characteristic along with other features of uncertainty pose a great challenge to effective uncertainty-aware visualization. This paper presents a new framework for modeling uncertainty and characterizing the evolution of the uncertainty information through analytical processes. Based on the framework, we have designed a visual metaphor called uncertainty flow to visually and intuitively summarize how uncertainty information propagates over the whole analysis pipeline. Our system allows analysts to interact with and analyze the uncertainty information at different levels of detail. Three experiments were conducted to demonstrate the effectiveness and intuitiveness of our design. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization uncertainty visual analytics visual analytics Ma, K.-L. uncertainty visualization uncertainty Wu, Y. Yuan, G. error ellipsoids uncertainty fusion uncertainty propagation uncertainty quantification covariance matrix ellipsoids infovis12--286 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Visualizing Network Traffic to Understand the Performance of Massively Parallel Simulations. The performance of massively parallel applications is often heavily impacted by the cost of communication among compute nodes. However, determining how to best use the network is a formidable task, made challenging by the ever increasing size and complexity of modern supercomputers. This paper applies visualization techniques to aid parallel application developers in understanding the network activity by enabling a detailed exploration of the flow of packets through the hardware interconnect. In order to visualize this large and complex data, we employ two linked views of the hardware network. The first is a 2D view, that represents the network structure as one of several simplified planar projections. This view is designed to allow a user to easily identify trends and patterns in the network traffic. The second is a 3D view that augments the 2D view by preserving the physical network topology and providing a context that is familiar to the application developers. Using the massively parallel multi-physics code pF3D as a case study, we demonstrate that our tool provides valuable insight that we use to explain and optimize pF3D's performance on an IBM Blue Gene/P system. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on data visualization network hardware case study insight layout performance evaluation network topology Landge, A.G. Levine, J.A. Bhatele, A. Isaacs, K.E. Gamblin, T. Schulz, M. Langer, S.H. Bremer, P.-T. Pascucci, V. performance analysis network traffic visualization projected graph layouts computational modeling hardware supercomputers infovis12--288 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Visualizing Student Histories Using Clustering and Composition. While intuitive time-series visualizations exist for common datasets, student course history data is difficult to represent using traditional visualization techniques due its concurrent nature. A visual composition process is developed and applied to reveal trends across various groupings. By working closely with educators, analytic strategies and techniques are developed to leverage the visualization composition to reveal unknown trends in the data. Furthermore, clustering algorithms are developed to group common course-grade histories for further analysis. Lastly, variations of the composition process are implemented to reveal subtle differences in the underlying data. These analytic tools and techniques enabled educators to confirm expected trends and to discover new ones. 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on clustering history data visualization market research image color analysis trajectory Trimm, D. Rheingans, P. desJardins, M. clustering aggregate visualization student performance analysis visualization composition history infovis12--291 10/16/2012 Visualization and Computer Graphics, IEEE Transactions on Whisper: Tracing the Spatiotemporal Process of Information Diffusion in Real Time. When and where is an idea dispersed? Social media, like Twitter, has been increasingly used for exchanging information, opinions and emotions about events that are happening across the world. Here we propose a novel visualization design, "Whisper", for tracing the process of information diffusion in social media in real time. Our design highlights three major characteristics of diffusion processes in social media: the temporal trend, social-spatial extent, and community response of a topic of interest. Such social, spatiotemporal processes are conveyed based on a sunflower metaphor whose seeds are often dispersed far away. In Whisper, we summarize the collective responses of communities on a given topic based on how tweets were retweeted by groups of users, through representing the sentiments extracted from the tweets, and tracing the pathways of retweets on a spatial hierarchical layout. We use an efficient flux line-drawing algorithm to trace multiple pathways so the temporal and spatial patterns can be identified even for a bursty event. A focused diffusion series highlights key roles such as opinion leaders in the diffusion process. We demonstrate how our design facilitates the understanding of when and where a piece of information is dispersed and what are the social responses of the crowd, for large-scale events including political campaigns and natural disasters. Initial feedback from domain experts suggests promising use for today's information consumption and dispersion in the wild. social 2012 InfoVis Visualization and Computer Graphics, IEEE Transactions on information visualization Liu, S. Qu, H. Cao, N. Lin, Y. Sun, X. Lazer, D. social media contagion information diffusion microblogging spatiotemporal patterns diffusion processes media monitoring real-time systems social network services twitter vast06--4035741 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Time Tree: Exploring Time Changing Hierarchies. Intelligence analysis often involves the task of gathering information about an organization. Knowledge about individuals in an organization and their relationships, often represented as a hierarchical organization chart, is crucial for understanding the organization. However, it is difficult for intelligence analysts to follow all individuals in an organization. Existing hierarchy visualizations have largely focused on the visualization of fixed structures and can not effectively depict the evolution of a hierarchy over time. We introduce TimeTree, a novel visualization tool designed to enable exploration of a changing hierarchy. TimeTree enables analysts to navigate the history of an organization, identify events associated with a specific entity (visualized on a TimeSlider), and explore an aggregate view of an individual's career path (a CareerTree). We demonstrate the utility of TimeTree by investigating a set of scenarios developed by an expert intelligence analyst. The scenarios are evaluated using a real dataset composed of eighteen thousand career events from more than eight thousand individuals. Insights gained from this analysis are presented visual analytics VAST intelligence analysis history Card, S.K. Bodnar, J.W. Heer, J. Suh, B. Pendleton, B.A. hierarchy hierarchies 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On tree visualization DOI tree timetree organizational chart time series data vast06--4035742 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Visual Exploration of Spatio-temporal Relationships for Scientific Data. Spatio-temporal relationships among features extracted from temporally-varying scientific datasets can provide useful information about the evolution of an individual feature and its interactions with other features. However, extracting such useful relationships without user guidance is cumbersome and often an error prone process. In this paper, we present a visual analysis system that interactively discovers such relationships from the trajectories of derived features. We describe analysis algorithms to derive various spatial and spatio-temporal relationships. A visual interface is presented using which the user can interactively select spatial and temporal extents to guide the knowledge discovery process. We show the usefulness of our proposed algorithms on datasets originating from computational fluid dynamics. We also demonstrate how the derived relationships can help in explaining the occurrence of critical events like merging and bifurcation of the vortices VAST Machiraju, R. 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Mehta, S. Parthasarathy, S. vast06--4035743 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Visual Analytics of Paleoceanographic Conditions. Decade scale oceanic phenomena like El Nino are correlated with weather anomalies all over the globe. Only by understanding the events that produced the climatic conditions in the past will it be possible to forecast abrupt climate changes and prevent disastrous consequences for human beings and their environment. Paleoceanography research is a collaborative effort that requires the analysis of paleo time-series, which are obtained from a number of independent techniques and instruments and produced by a variety of different researchers and/or laboratories. The complexity of these phenomena that consist of massive, dynamic and often conflicting data can only be faced by means of analytical reasoning supported by a highly interactive visual interface. This paper presents an interactive visual analysis environment for paleoceanography that permits to gain insight into the paleodata and allow the control and steering of the analytical methods involved in the reconstruction of the climatic conditions of the past visual analytics VAST insight 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Theron, R. vast06--4035744 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Avian Flu Case Study with nSpace and GeoTime. GeoTime and nSpace are new analysis tools that provide innovative visual analytic capabilities. This paper uses an epidemiology analysis scenario to illustrate and discuss these new investigative methods and techniques. In addition, this case study is an exploration and demonstration of the analytical synergy achieved by combining GeoTime's geo-temporal analysis capabilities, with the rapid information triage, scanning and sense-making provided by nSpace. A fictional analyst works through the scenario from the initial brainstorming through to a final collaboration and report. With the efficient knowledge acquisition and insights into large amounts of documents, there is more time for the analyst to reason about the problem and imagine ways to mitigate threats. The use of both nSpace and GeoTime initiated a synergistic exchange of ideas, where hypotheses generated in either software tool could be cross-referenced, refuted, and supported by the other tool visual analytics VAST collaboration case study information visualization Wright, W. Harper, R. human information interaction 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On sensemaking Proulx, P. Tandon, S. Bodnar, A. Schroh, D. geo-spatial information systems temporal analysis user centered design vast06--4035745 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Visual Analysis of Historic Hotel Visitation Patterns. Understanding the space and time characteristics of human interaction in complex social networks is a critical component of visual tools for intelligence analysis, consumer behavior analysis, and human geography. Visual identification and comparison of patterns of recurring events is an essential feature of such tools. In this paper, we describe a tool for exploring hotel visitation patterns in and around Rebersburg, Pennsylvania from 1898-1900. The tool uses a wrapping spreadsheet technique, called reruns, to display cyclic patterns of geographic events in multiple overlapping natural and artificial calendars. Implemented as an improvise visualization, the tool is in active development through a iterative process of data collection, hypothesis, design, discovery, and evaluation in close collaboration with historical geographers. Several discoveries have inspired ongoing data collection and plans to expand exploration to include historic weather records and railroad schedules. Distributed online evaluations of usability and usefulness have resulted in numerous feature and design recommendations interaction VAST collaboration social geographic evaluation intelligence analysis usability Weaver, C. Robinson, A.C. 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On MacEachren, A.M. Fyfe, D. Holdsworth, D. Peuquet, D.J. vast06--4035746 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On D-Dupe: An Interactive Tool for Entity Resolution in Social Networks. Visualizing and analyzing social networks is a challenging problem that has been receiving growing attention. An important first step, before analysis can begin, is ensuring that the data is accurate. A common data quality problem is that the data may inadvertently contain several distinct references to the same underlying entity; the process of reconciling these references is called entity-resolution. D-Dupe is an interactive tool that combines data mining algorithms for entity resolution with a task-specific network visualization. Users cope with complexity of cleaning large networks by focusing on a small subnetwork containing a potential duplicate pair. The subnetwork highlights relationships in the social network, making the common relationships easy to visually identify. D-Dupe users resolve ambiguities either by merging nodes or by marking them distinct. The entity resolution process is iterative: as pairs of nodes are resolved, additional duplicates may be revealed; therefore, resolution decisions are often chained together. We give examples of how users can flexibly apply sequences of actions to produce a high quality entity resolution result. We illustrate and evaluate the benefits of D-Dupe on three bibliographic collections. Two of the datasets had already been cleaned, and therefore should not have contained duplicates; despite this fact, many duplicates were rapidly identified using D-Dupe's unique combination of entity resolution algorithms within a task-specific visual interface VAST social network Shneiderman, B. data mining 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Bilgic, M. Licamele, L. Getoor, L. vast06--4035747 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Interactive Visual Synthesis of Analytic Knowledge. A visual investigation involves both the examination of existing information and the synthesis of new analytic knowledge. This is a progressive process in which newly synthesized knowledge becomes the foundation for future discovery. In this paper, we present a novel system supporting interactive, progressive synthesis of analytic knowledge. Here we use the term "analytic knowledge" to refer to concepts that a user derives from existing data along with the evidence supporting such concepts. Unlike existing visual analytic-tools, which typically support only exploration of existing information, our system offers two unique features. First, we support user-system cooperative visual synthesis of analytic knowledge from existing data. Specifically, users can visually define new concepts by annotating existing information, and refine partially formed concepts by linking additional evidence or manipulating related concepts. In response to user actions, our system can automatically manage the evolving corpus of synthesized knowledge and its corresponding evidence. Second, we support progressive visual analysis of synthesized knowledge. This feature allows analysts to visually explore both existing knowledge and synthesized knowledge, dynamically incorporating earlier analytic conclusions into the ensuing discovery process. We have applied our system to two complex but very different analytic applications. Our preliminary evaluation shows the promise of our work VAST evaluation Zhou, M.X. Gotz, D. 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Aggarwal, V. vast06--4035748 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Visual Analysis of Conflicting Opinions. Understanding the nature and dynamics of conflicting opinions is a profound and challenging issue. In this paper we address several aspects of the issue through a study of more than 3,000 Amazon customer reviews of the controversial bestseller The Da Vinci Code, including 1,738 positive and 918 negative reviews. The study is motivated by critical questions such as: what are the differences between positive and negative reviews? What is the origin of a particular opinion? How do these opinions change over time? To what extent can differentiating features be identified from unstructured text? How accurately can these features predict the category of a review? We first analyze terminology variations in these reviews in terms of syntactic, semantic, and statistic associations identified by TermWatch and use term variation patterns to depict underlying topics. We then select the most predictive terms based on log likelihood tests and demonstrate that this small set of terms classifies over 70% of the conflicting reviews correctly. This feature selection process reduces the dimensionality of the feature space from more than 20,000 dimensions to a couple of hundreds. We utilize automatically generated decision trees to facilitate the understanding of conflicting opinions in terms of these highly predictive terms. This study also uses a number of visualization and modeling tools to identify not only what positive and negative reviews have in common, but also they differ and evolve over time VAST visual analytics text Weaver, C. 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Chen, C. sensemaking Ibekwe-SanJuan, F. SanJuan, E. conflicting opinions decision tree predictive text analysis terminology variation vast06--4035749 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Have Green A¢¯ A Visual Analytics Framework for Large Semantic Graphs. A semantic graph is a network of heterogeneous nodes and links annotated with a domain ontology. In intelligence analysis, investigators use semantic graphs to organize concepts and relationships as graph nodes and links in hopes of discovering key trends, patterns, and insights. However, as new information continues to arrive from a multitude of sources, the size and complexity of the semantic graphs will soon overwhelm an investigator's cognitive capacity to carry out significant analyses. We introduce a powerful visual analytics framework designed to enhance investigators' natural analytical capabilities to comprehend and analyze large semantic graphs. The paper describes the overall framework design, presents major development accomplishments to date, and discusses future directions of a new visual analytics system known as Have Green visual analytics VAST network graph intelligence analysis Thomas, J. Wong, P.C. Foote, H. Mackey, P. 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Chin, G. vast06--4035750 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Exploring Large-Scale Video News via Interactive Visualization. In this paper, we have developed a novel visualization framework to enable more effective visual analysis of large-scale news videos, where keyframes and keywords are automatically extracted from news video clips and visually represented according to their interestingness measurement to help audiences rind news stories of interest at first glance. A computational approach is also developed to quantify the interestingness measurement of video clips. Our experimental results have shown that our techniques for intelligent news video analysis have the capacity to enable more effective visualization of large-scale news videos. Our news video visualization system is very useful for security applications and for general audiences to quickly find news topics of interest from among many channels VAST Ribarsky, W. Yang, J. security Luo, H. Fan, J. Satoh, S. 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On vast06--4035751 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Interactive Visualization and Analysis of Network and Sensor Data on Mobile Devices. Mobile devices are rapidly gaining popularity due to their small size and their wide range of functionality. With the constant improvement in wireless network access, they are an attractive option not only for day to day use. but also for in-field analytics by first responders in widespread areas. However, their limited processing, display, graphics and power resources pose a major challenge in developing effective applications. Nevertheless, they are vital for rapid decision making in emergencies when combined with appropriate analysis tools. In this paper, we present an efficient, interactive visual analytic system using a PDA to visualize network information from Purdue's Ross-Ade Stadium during football games as an example of in-held data analytics combined with text and video analysis. With our system, we can monitor the distribution of attendees with mobile devices throughout the stadium through their access of information and association/disassociation from wireless access points, enabling the detection of crowd movement and event activity. Through correlative visualization and analysis of synchronized video (instant replay video) and text information (play statistics) with the network activity, we can provide insightful information to network monitoring personnel, safety personnel and analysts. This work provides a demonstration and testbed for mobile sensor analytics that will help to improve network performance and provide safety personnel with information for better emergency planning and guidance VAST network text Ebert, D.S. statistics Jang, Y. 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Pattath, A. Bue, B. Zhong, X. Aulf, A. Coyle, E. vast06--4035752 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On NetLens: Iterative Exploration of Content-Actor Network Data. Networks have remained a challenge for information retrieval and visualization because of the rich set of tasks that users want to accomplish. This paper offers an abstract content-actor network data model, a classification of tasks, and a tool to support them. The NetLens interface was designed around the abstract content-actor network data model to allow users to pose a series of elementary queries and iteratively refine visual overviews and sorted lists. This enables the support of complex queries that are traditionally hard to specify. NetLens is general and scalable in that it applies to any dataset that can be represented with our abstract data model. This paper describes NetLens applying a subset of the ACM Digital Library consisting of about 4,000 papers from the CM I conference written by about 6,000 authors. In addition, we are now working on a collection of half a million emails, and a dataset of legal cases VAST network Lee, B. human-computer interaction Plaisant, C. information visualization 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On user interface Bederson, B.B. network visualization digital library Kang, H. content-actor network data incremental data exploration iterative query refinement piccolo vast06--4035753 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Interactive Wormhole Detection in Large Scale Wireless Networks. Wormhole attacks in wireless networks can severely deteriorate the network performance and compromise the security through spoiling the routing protocols and weakening the security enhancements. This paper develops an approach, interactive visualization of wormholes (IVoW), to monitor and detect such attacks in large scale wireless networks in real time. We characterize the topology features of a network under wormhole attacks through the node position changes and visualize the information at dynamically adjusted scales. We integrate an automatic detection algorithm with appropriate user interactions to handle complicated scenarios that include a large number of moving nodes and multiple worm-hole attackers. Various visual forms have been adopted to assist the understanding and analysis of the reconstructed network topology and improve the detection accuracy. Extended simulation has demonstrated that the proposed approach can effectively locate the fake neighbor connections without introducing many false alarms. IVoW does not require the wireless nodes to be equipped with any special hardware, thus avoiding any additional cost. The proposed approach demonstrates that interactive visualization can be successfully combined with network security mechanisms to greatly improve the intrusion detection capabilities VAST network hardware security 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Wang, W. Lu, A. vast06--4035754 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Enhancing Visual Analysis of Network Traffic Using a Knowledge Representation. This paper presents a network traffic analysis system that couples visual analysis with a declarative knowledge representation. The system supports multiple iterations of the sense-making loop of analytic reasoning by allowing users to save discoveries as they are found and to reuse them in future iterations. We show how the knowledge representation can be used to improve both the visual representations and the basic analytical tasks of filtering and changing level of detail. We describe how the system can be used to produce models of network patterns, and show results from classifying one day of network traffic in our laboratory VAST network visual analysis Hanrahan, P. Xiao, L. Gerth, J. 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On network traffic visualization vast06--4035755 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Accelerating Network Traffic Analytics Using Query-Driven Visualization. Realizing operational analytics solutions where large and complex data must be analyzed in a time-critical fashion entails integrating many different types of technology. This paper focuses on an interdisciplinary combination of scientific data management and visualization/analysis technologies targeted at reducing the time required for data filtering, querying, hypothesis testing and knowledge discovery in the domain of network connection data analysis. We show that use of compressed bitmap indexing can quickly answer queries in an interactive visual data analysis application, and compare its performance with two alternatives for serial and parallel filtering/querying on 2.5 billion records' worth of network connection data collected over a period of 42 weeks. Our approach to visual network connection data exploration centers on two primary factors: interactive ad-hoc and multiresolution query formulation and execution over n dimensions and visual display of the n-dimensional histogram results. This combination is applied in a case study to detect a distributed network scan and to then identify the set of remote hosts participating in the attack. Our approach is sufficiently general to be applied to a diverse set of data understanding problems as well as used in conjunction with a diverse set of analysis and visualization tools visual analytics VAST network case study 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On data mining network security Bethel, E.W. Campbell, S. Dart, E. Stockinger, K. Wu, K. query-driven visualization vast06--4035756 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Monitoring Network Traffic with Radial Traffic Analyzer. Extensive spread of malicious code on the Internet and also within intranets has risen the user's concern about what kind of data is transferred between her or his computer and other hosts on the network. Visual analysis of this kind of information is a challenging task, due to the complexity and volume of the data type considered, and requires special design of appropriate visualization techniques. In this paper, we present a scalable visualization toolkit for analyzing network activity of computer hosts on a network. The visualization combines network packet volume and type distribution information with geographic information, enabling the analyst to use geographic distortion techniques such as the HistoMap technique to become aware of the traffic components in the course of the analysis. The presented analysis tool is especially useful to compare important network load characteristics in a geographically aware display, to relate communication partners, and to identify the type of network traffic occurring. The results of the analysis are helpful in understanding typical network communication activities, and in anticipating potential performance bottlenecks or problems. It is suited for both off-line analysis of historic data, and via animation for on-line monitoring of packet-based network traffic in real time VAST visual analytics geographic network information visualization Keim, D.A. Schneidewind, J. Schreck, T. radial animation toolkit 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On distortion Mansmann, F. geography-based solutions network traffic monitoring vast06--4035757 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Toward a Multi-Analyst, Collaborative Framework for Visual Analytics. We describe a framework for the display of complex, multidimensional data, designed to facilitate exploration, analysis, and collaboration among multiple analysts. This framework aims to support human collaboration by making it easier to share representations, to translate from one point of view to another, to explain arguments, to update conclusions when underlying assumptions change, and to justify or account for decisions or actions. Multidimensional visualization techniques are used with interactive, context-sensitive, and tunable graphs. Visual representations are flexibly generated using a knowledge representation scheme based on annotated logic; this enables not only tracking and fusing different viewpoints, but also unpacking them. Fusing representations supports the creation of multidimensional meta-displays as well as the translation or mapping from one point of view to another. At the same time, analysts also need to be able to unpack one another's complex chains of reasoning, especially if they have reached different conclusions, and to determine the implications, if any, when underlying assumptions or evidence turn out to be false. The framework enables us to support a variety of scenarios as well as to systematically generate and test experimental hypotheses about the impact of different kinds of visual representations upon interactive collaboration by teams of distributed analysts visual analytics VAST collaboration visual analytics Ramakrishnan, I.V. Mueller, K. 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Kaufman, A. Brennan, S.E. Zelinsky, G. Warren, D.S. collaborative and distributed visualization data management and knowledge representation visual knowledge discovery vast06--4035758 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Collaborative Visual Analytics: Inferring from the Spatial Organization and Collaborative Use of Information. We introduce a visual analytics environment for the support of remote-collaborative sense-making activities. Team members use their individual graphical interfaces to collect, organize and comprehend task-relevant information relative to their areas of expertise. A system of computational agents infers possible relationships among information items through the analysis of the spatial and temporal organization and collaborative use of information. The computational agents support the exchange of information among team members to converge their individual contributions. Our system allows users to navigate vast amounts of shared information effectively and remotely dispersed team members to work independently without diverting from common objectives as well as to minimize the necessary amount of verbal communication visual analytics VAST 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Keel, P.E. vast06--4035759 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Beyond Usability: Evaluation Aspects of Visual Analytic Environments. A new field of research, visual analytics, has been introduced. This has been defined as "the science of analytical reasoning facilitated by interactive visual interfaces" (Thomas and Cook, 2005). Visual analytic environments, therefore, support analytical reasoning using visual representations and interactions, with data representations and transformation capabilities, to support production, presentation, and dissemination. As researchers begin to develop visual analytic environments, it is advantageous to develop metrics and methodologies to help researchers measure the progress of their work and understand the impact their work has on the users who work in such environments. This paper presents five areas or aspects of visual analytic environments that should be considered as metrics and methodologies for evaluation are developed. Evaluation aspects need to include usability, but it is necessary to go beyond basic usability. The areas of situation awareness, collaboration, interaction, creativity, and utility are proposed as the five evaluation areas for initial consideration. The steps that need to be undertaken to develop systematic evaluation methodologies and metrics for visual analytic environments are outlined interaction visual analytics VAST visualization collaboration evaluation usability metrics Scholtz, J. awareness 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On metrics analytic environments vast06--4035760 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Visualizing the Performance of Computational Linguistics Algorithms. We have built a visualization system and analysis portal for evaluating the performance of computational linguistics algorithms. Our system focuses on algorithms that classify and cluster documents by assigning weights to words and scoring each document against high dimensional reference concept vectors. The visualization and algorithm analysis techniques include confusion matrices, ROC curves, document visualizations showing word importance, and interactive reports. One of the unique aspects of our system is that the visualizations are thin-client Web-based components built using SVG visualization components VAST document cluster Eick, S.G. 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Mauger, J. Ratner, A. AJAX ROC curves SVG confusion matrices document categorization thin-client vast06--4035761 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Scentindex: Conceptually Reorganizing Subject Indexes for Reading. A great deal of analytical work is done in the context of reading, in digesting the semantics of the material, the identification of important entities, and capturing the relationship between entities. Visual analytic environments, therefore, must encompass reading tools that enable the rapid digestion of large amount of reading material. Other than plain text search, subject indexes, and basic highlighting, tools are needed for rapid foraging of text. In this paper, we describe a technique that presents an enhanced subject index for a book by conceptually reorganizing it to suit particular expressed user information needs. Users first enter information needs via keywords describing the concepts they are trying to retrieve and comprehend. Then our system, called ScentIndex, computes what index entries are conceptually related and reorganizes and displays these index entries on a single page. We also provide a number of navigational cues to help users peruse over this list of index entries and find relevant passages quickly. Compared to regular reading of a paper book, our study showed that users are more efficient and more accurate in finding, comparing, and comprehending material in our system VAST text Card, S.K. Chi, E.H. 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Hong, L. Heiser, J. book index information scent contextualization ebooks personalized information access vast06--4035762 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On A Visual Interface for Multivariate Temporal Data: Finding Patterns of Events across Multiple Histories. Finding patterns of events over time is important in searching patient histories, Web logs, news stories, and criminal activities. This paper presents PatternFinder, an integrated interface for query and result-set visualization for search and discovery of temporal patterns within multivariate and categorical data sets. We define temporal patterns as sequences of events with inter-event time spans. PatternFinder allows users to specify the attributes of events and time spans to produce powerful pattern queries that are difficult to express with other formalisms. We characterize the range of queries PatternFinder supports as users vary the specificity at which events and time spans are defined. Pattern Finder's query capabilities together with coupled ball-and-chain and tabular visualizations enable users to effectively query, explore and analyze event patterns both within and across data entities (e.g. patient histories, terrorist groups, Web logs, etc.) VAST categorical Shneiderman, B. information visualization 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Fails, J.A. Karlson, A.K. Shahamat, L. temporal query user interface vast06--4035763 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On User Interfaces for the Exploration of Hierarchical Multi-dimensional Data. A variety of user interfaces have been developed to support the querying of hierarchical multi-dimensional data in an OLAP setting such as pivot tables and Polaris. They are used to regularly check portions of a dataset and to explore a new dataset for the first time. In this paper, we establish criteria for OLAP user interface capabilities to facilitate comparison. Two criteria are the number of displayed dimensions along which comparisons can be made and the number of dimensions that are viewable at once - visual comparison depth and width. We argue that interfaces with greater visual comparison depth support regular checking of known data by users that know roughly where to look, while interfaces with greater comparison width support exploration of new data by users that have no a priori starting point and need to scan all dimensions. Pivot tables and Polaris are examples of the former. The main contribution of this paper is to introduce a new scalable interface that uses parallel dimension axis which supports the latter, greater visual comparison width. We compare our approach to both table based and parallel coordinate based interfaces. We present an implementation of our interface SGViewer, user scenarios and provide an evaluation that supports the usability of our interface VAST visualization evaluation usability parallel coordinates 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Sifer, M. data exploration OLAP vast06--4035764 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Exploratory Visualization of Multivariate Data with Variable Quality. Real-world data is known to be imperfect, suffering from various forms of defects such as sensor variability, estimation errors, uncertainty, human errors in data entry, and gaps in data gathering. Analysis conducted on variable quality data can lead to inaccurate or incorrect results. An effective visualization system must make users aware of the quality of their data by explicitly conveying not only the actual data content, but also its quality attributes. While some research has been conducted on visualizing uncertainty in spatio-temporal data and univariate data, little work has been reported on extending this capability into multivariate data visualization. In this paper we describe our approach to the problem of visually exploring multivariate data with variable quality. As a foundation, we propose a general approach to defining quality measures for tabular data, in which data may experience quality problems at three granularities: individual data values, complete records, and specific dimensions. We then present two approaches to visual mapping of quality information into display space. In particular, one solution embeds the quality measures as explicit values into the original dataset by regarding value quality and record quality as new data dimensions. The other solution is to superimpose the quality information within the data visualizations using additional visual variables. We also report on user studies conducted to assess alternate mappings of quality attributes to visual variables for the second method. In addition, we describe case studies that expose some of the advantages and disadvantages of these two approaches VAST uncertainty Ward, M.O. Rundensteiner, E.A. 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Huang, S. Xie, Z. vast06--4035765 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Semantic Image Browser: Bridging Information Visualization with Automated Intelligent Image Analysis. Browsing and retrieving images from large image collections are becoming common and important activities. Semantic image analysis techniques, which automatically detect high level semantic contents of images for annotation, are promising solutions toward this problem. However, few efforts have been made to convey the annotation results to users in an intuitive manner to enable effective image browsing and retrieval. There is also a lack of methods to monitor and evaluate the automatic image analysis algorithms due to the high dimensional nature of image data, features, and contents. In this paper, we propose a novel, scalable semantic image browser by applying existing information visualization techniques to semantic image analysis. This browser not only allows users to effectively browse and search in large image databases according to the semantic content of images, but also allows analysts to evaluate their annotation process through interactive visual exploration. The major visualization components of this browser are multi-dimensional scaling (MDS) based image layout, the value and relation (VaR) display that allows effective high dimensional visualization without dimension reduction, and a rich set of interaction tools such as search by sample images and content relationship detection. Our preliminary user study showed that the browser was easy to use and understand, and effective in supporting image browsing and retrieval tasks interaction VAST user study Ribarsky, W. Yang, J. dimension reduction Ward, M.O. Luo, H. Fan, J. 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Hubball, D. Gao, Y. vast06--4035766 10/31/2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On Pixnostics: Towards Measuring the Value of Visualization. During the last two decades a wide variety of advanced methods for the visual exploration of large data sets have been proposed. For most of these techniques user interaction has become a crucial element, since there are many situations in which a user or an analyst has to select the right parameter settings from among many or select a subset of the available attribute space for the visualization process, in order to construct valuable visualizations that provide insight, into the data and reveal interesting patterns. The right choice of input parameters is often essential, since suboptimal parameter settings or the investigation of irrelevant data dimensions make the exploration process more time consuming and may result in wrong conclusions. In this paper we propose a novel method for automatically determining meaningful parameter- and attribute settings based on the information content of the resulting visualizations. Our technique called Pixnostics, in analogy to Scagnostics (Wilkinson et al., 2005), automatically analyses pixel images resulting from diverse parameter mappings and ranks them according to the potential value for the user. This allows a more effective and more efficient visual data analysis process, since the attribute/parameter space is reduced to meaningful selections and thus the analyst obtains faster insight into the data. Real world applications are provided to show the benefit of the proposed approach interaction VAST insight Keim, D.A. pixel Schneidewind, J. Sips, M. 2006 Visual Analytics Science And Technology, 2006 IEEE Symposium On vast07--4388990 10/30/2007 Visual Analytics Science and Technology, 2007. VAST 2007. IEEE Symposium on Activity Analysis Using Spatio-Temporal Trajectory Volumes in Surveillance Applications. In this paper, we present a system to analyze activities and detect anomalies in a surveillance application, which exploits the intuition and experience of security and surveillance experts through an easy- to-use visual feedback loop. The multi-scale and location specific nature of behavior patterns in space and time is captured using a wavelet-based feature descriptor. The system learns the fundamental descriptions of the behavior patterns in a semi-supervised fashion by the higher order singular value decomposition of the space described by the training data. This training process is guided and refined by the users in an intuitive fashion. Anomalies are detected by projecting the test data into this multi-linear space and are visualized by the system to direct the attention of the user to potential problem spots. We tested our system on real-world surveillance data, and it satisfied the security concerns of the environment. VAST 2007 Visual Analytics Science and Technology, 2007. VAST 2007. IEEE Symposium on security surveillance Machiraju, R. Janoos, F. Singh, S. Irfanoglu, O. Parent, R. HOSVD anomaly detection trajectory wavelets vast07--4388991 10/30/2007 Visual Analytics Science and Technology, 2007. VAST 2007. IEEE Symposium on FemaRepViz: Automatic Extraction and Geo-Temporal Visualization of FEMA National Situation Updates. An architecture for visualizing information extracted from text documents is proposed. In conformance with this architecture, a toolkit, FemaRepViz, has been implemented to extract and visualize temporal, geospatial, and summarized information from FEMA national update reports. Preliminary tests have shown satisfactory accuracy for FEMARepViz. A central component of the architecture is an entity extractor that extracts named entities like person names, location names, temporal references, etc. FEMARepViz is based on FactXtractor, an entity-extractor that works on text documents. The information extracted using FactXtractor is processed using GeoTagger, a geographical name disambiguation tool based on a novel clustering-based disambiguation algorithm. To extract relationships among entities, we propose a machine-learning based algorithm that uses a novel stripped dependency tree kernel. We illustrate and evaluate the usefulness of our system on the FEMA National Situation Updates. Daily reports are fetched by FEMARepViz from the FEMA website, segmented into coherent sections and each section is classified into one of several known incident types. We use concept Vista, Google maps and Google earth to visualize the events extracted from the text reports and allow the user to interactively filter the topics, locations, and time-periods of interest to create a visual analytics toolkit that is useful for rapid analysis of events reported in a large set of text documents. visual analytics visual analytics VAST text clustering geospatial filter 2007 Visual Analytics Science and Technology, 2007. VAST 2007. IEEE Symposium on toolkit knowledge discovery Pan, C.-C. Mitra, P. geo-temporal visualization geospatial analytics text processing vast07--4388992 10/30/2007 Visual Analytics Science and Technology, 2007. VAST 2007. IEEE Symposium on Stories in GeoTime. A story is a powerful abstraction used by intelligence analysts to conceptualize threats and understand patterns as part of the analytical process. This paper demonstrates a system that detects geo-temporal patterns and integrates story narration to increase analytic sense-making cohesion in GeoTime. The GeoTime geo-temporal event visualization tool was augmented with a story system that uses narratives, hypertext linked visualizations, visual annotations, and pattern detection to create an environment for analytic exploration and communication, thereby assisting the analyst in identifying, extracting, arranging and presenting stories within the data The story system lets analysts operate at the story level with higher-level abstractions of data, such as behaviors and events, while staying connected to the evidence. The story system was developed and evaluated in collaboration with analysts. visual analytics VAST collaboration Wright, W. Kapler, T. Harper, R. Eccles, R. 2007 Visual Analytics Science and Technology, 2007. VAST 2007. IEEE Symposium on human information interaction narrative pattern detection sensemaking story making storytelling vast